PACT PROGRAMME Airway management

AN ESIICM MULT TIDISCIPLIN NARY DISTA ANCE LEAR RNING PROG GRAMME FOR IN NTENSIVE CARE A TRAIN NING

Aiirway ma manag gem men nt Skillls and techniiques Upd date 20 011 (pd df) Modulle Author rs (Updatte 2011) Gavin L LAVERY

Dept of Cliinical Anaessthesia, Royyal Victoria nd Hospital, Belfast, B Norrthern Irelan

McCLOSK KEY Brian M

Regional Intensive Ca are, Royal V Victoria Hosspital, Belfast, No orthern Ireland

Eamon n McCOY

Royal Victoria Hospittal, Belfast, Northern Ireland

Modulle Author rs (first edition) e Gavin L LAVERY

Dept of Cliinical Anaessthesia, Royyal Victoria Hospital, Belfast, B Norrthern Irelan nd

McCLOSK KEY Brian M

Regional Intensive Ca are, Royal V Victoria Hosspital, Belfast, No orthern Ireland

Modulee Reviewers

Per Nellgårrd, Janice Zimmerman Z n

Section Editor

Anders Larrsson

Airway management Update 2011 Editor-in-Chief

Dermot Phelan, Intensive Care Dept, Mater Hospital/University College Dublin, Ireland

Deputy Editor-in-Chief

Francesca Rubulotta, Imperial College, Charing Cross Hospital, London, UK

Medical Copy-editor

Charles Hinds, Barts and The London School of Medicine and Dentistry

Self-assessment Author

Hans Flaatten, Bergen, Norway

Editorial Manager

Kathleen Brown, Triwords Limited, Tayport, UK

Business Manager

Estelle Flament, ESICM, Brussels, Belgium

Chair of Education and Training

Marco Maggiorini, Zurich, Switzerland

Committee

PACT Editorial Board Editor-in-Chief

Dermot Phelan

Deputy Editor-in-Chief

Francesca Rubulotta

Respiratory failure

Anders Larsson

Cardiovascular critical care

Jan Poelaert/Marco Maggiorini

Neuro-critical care and Emergency

Mauro Oddo

medicine Critical Care informatics, management

Carl Waldmann

and outcome Environmental hazards and

Janice Zimmerman

Obstetric critical care Infection/inflammation and Sepsis

Johan Groeneveld

Kidney Injury and Metabolism.

Charles Hinds

Abdomen and nutrition Peri-operative ICM/surgery and

Torsten Schröder

imaging Professional development and Ethics

Gavin Lavery

Education and assessment

Lia Fluit

Consultant to the PACT Board

Graham Ramsay

Copyright© 2011. European Society of Intensive Care Medicine. All rights reserved.

Airway management Learning objectives: After studying this module on Airway management, you should be able to: 1. 2. 3. 4. 5.

Make a complete assessment of the airway Explain indications, contraindications and techniques for different methods of securing the airway Describe correct tracheal tube positioning and confirmation of tracheal tube placement Identify techniques to deal with the anticipated and unanticipated difficult airway Detail pitfalls in airway management.

Contents Introduction ..................................................................................................................... 1  1. Assessment of airway .................................................................................................. 2  Airway patency ............................................................................................................ 2  Recognition of injuries to airway or other structures............................................. 3  Recognition of anatomic variations/abnormalities................................................ 4  Protective reflexes ....................................................................................................... 6  Respiratory drive ........................................................................................................ 7  Inspired oxygen concentration ................................................................................... 8  Identification of signs of hypoxaemia ..................................................................... 8  Identification of dyspnoea ...................................................................................... 9  2. Airway interventions ................................................................................................ 10  Patient positioning .................................................................................................... 10  Clearing the airway .................................................................................................... 11  Triple airway manoeuvre ...........................................................................................12  Artificial airway ..........................................................................................................12  Oropharyngeal airway ............................................................................................12  Nasopharyngeal airway ..........................................................................................13  Oxygenation and ventilation......................................................................................14  Variable flow face-mask .........................................................................................14  Manual ventilation using a mask ...........................................................................14  Apnoeic oxygenation .............................................................................................. 15  Tracheal intubation....................................................................................................16  Orotracheal intubation ........................................................................................... 17  Nasotracheal intubation ........................................................................................ 20  Fibre optic intubation ................................................................................................21  Contraindications (All relative) ............................................................................ 22  Advantages of fibre optic intubation..................................................................... 22  Conduct of fibre optic intubation .......................................................................... 22  Laryngeal mask airway ............................................................................................. 24  Developments of Laryngeal Mask Airway ............................................................ 25  Intubating laryngeal mask airway ........................................................................ 25  Oesophageal-tracheal double lumen device ............................................................. 26  Cricothyroidotomy .................................................................................................... 26  Equipment ............................................................................................................. 27  Seldinger technique ............................................................................................... 27  Ventilation through the cricothyroidotomy.......................................................... 27  Tracheostomy ............................................................................................................ 28  Timing of tracheostomy: early versus late ............................................................ 29  Percutaneous tracheostomy .................................................................................. 29  Tracheostomy tubes ...............................................................................................31  3. Recognition of effective ventilation .......................................................................... 32  Correct tracheal tube positioning ............................................................................. 32  Anatomy of the airways ......................................................................................... 32  Confirmation of tracheal tube placement................................................................. 32  Visualising the tube passing into the trachea ....................................................... 33  Chest wall movement on manual ventilation ....................................................... 33  Presence of water vapour condensing on the tracheal tube (‘misting’) ............... 33  Auscultation of breath sounds .............................................................................. 33  Compliance of the reservoir bag ........................................................................... 33  End-tidal carbon dioxide ...................................................................................... 33  Negative pressure devices ..................................................................................... 34  Fibre optic confirmation ....................................................................................... 34 

Radiology ............................................................................................................... 34  4. The difficult airway: algorithms & adjuncts to management .................................. 36  Difficult airway guidelines ........................................................................................ 36  Difficult intubation ................................................................................................... 37  Anticipated difficult intubation ............................................................................ 37  Unanticipated difficult intubation ........................................................................ 39  Failure to intubate and failure to ventilate ........................................................... 44  Extubation of the difficult airway ............................................................................. 46  Airway exchange catheter ..................................................................................... 46  5. Pitfalls in airway management ................................................................................. 47  Ineffective breathing despite artificial airway .......................................................... 47  Ineffective manual mask ventilation despite artificial e.g. oropharyngeal airway .. 47  One-sided intubation and ventilation ...................................................................... 48  Tube obstruction ....................................................................................................... 49  Tracheal tube obstruction ..................................................................................... 49  Tracheostomy tube obstruction ............................................................................ 50  Tube displacement ..................................................................................................... 51  Tracheal tubes ........................................................................................................ 51  Tracheostomy tubes ............................................................................................... 51  Conclusion .................................................................................................................... 52  Self-assessment............................................................................................................. 53  Patient challenges ......................................................................................................... 57 

Introdu uction

INTR RODUCT TION A Airway man nagement is the first sstep in resu uscitation of the crritically ill patient. Th here are baasic airway y manoeuvrres that can n bee learned quickly q by medical m an nd non-meedical staff and ad dvanced aiirway mano oeuvres th hat require training an nd exxperience to t be used appropriattely. Airwa ay managem ment may bee achieved simply by confirmin ng the patieent has an un nobstructeed airway and a by supp plying sup pplemental oxygen. Al Alternativelly it may re equire com mplex interv ventions su uch as trracheal intu ubation, fib bre optic teechniques or the esta ablishmentt off a surgicall airway.

Airw way skills require kno owledge, judgm ment and clin nical skill

he clinician n who take es care of th he criticallly ill patien nt should h have the ab bility to: Th   

Ma ake a rapid d and comp plete assesssment of the airway Seecure the aiirway by diifferent meethods Bee familiar with w algoritthms for difficult airw way managgement.

Th he sourcess below con ntain much h useful infformation on airway anatomy, causes off airway ob bstruction and airwayy managem ment. These referencees should be b read beefore comp pletion of Task T 1.

M Mort TC, Gab brielli A, Co oons TJ, Beh hringer EC. Airway Ma anagement. In: Gabriellli A, Layyon AJ, Yu M, editors. Civetta, Tay ylor and Kirrby’s Criticaal Care. 4th h ed. Ph hiladelphia:: Lippincottt Williams and a Wilkinss; 2009. ISB BN 978-07817-6869-6. pp. 519–556 Laavery GG, Jamison J CA. Airway maanagement in the criticcally ill adullt. In: Parrilllo, JE, Dellinger RP, ed ditors. Critiical Care Medicine: Priinciples of Diagn nosis and Management M t in the Adu ult. 3rd ed. Philadelphia P a: Mosby Elseviier; 2008. ISBN I 978-0 0-323-048411-5. pp. 17– –37

[1]

Task 1. Asssessment of airway a

1. AS SSESSM MENT OF F AIRW WAY A Assessmentt of the airw way can bee considereed in four parts. p

   

A Airway pa atency

Respiratory drive ve

Prrotective reflexes

Inspired O2 concentrration

Airwa ay patency y – a partiaal or compllete obstru uction will ccompromise ventiilation of th he lungs an nd thereforre gas exch hange. Proteective refle exes – thesee help maiintain patency and wi will prevent aspirration of material m into o the lowerr (pulmona ary) airwayys. Respiratory driive – a pateent and seccure airway y is of no vvalue if gass is not being g exchange ed between n the exteriior and the e pulmonarry alveoli. Inspiired oxygen n concentrration – ga as entering the pulmoonary alveo oli must have an adequa ate oxygen concentra ation.

A Airway patency p A Airway obsttruction is most frequ uently due to reduced d muscle to one allowin ng the tong gue to fall b backwards against th he posteriorr ph haryngeal wall thus blocking b th he airway. This T often happens w when an obttunded or anaesthetiised patien nt is lying supine.

A deepressed level of consciiousness is the greatest risk fa actor for airway obsstruction

©Janet Fon ng 2011; htttp://www.aicc.cuhk.edu.h hk/web8/Hi% %20res/Triplle%20manoeeuvre1.jpg

Th he table beelow lists other o frequ uent causess of airway obstructioon. L Location O Oropharyn nx

Cause e Presen nce of blood Presen nce of mucus Presen nce of vomitus Presen nce of foreiign bodies [2]

Task 1. Asssessment of airway a

U Upper airw ways

ma Oedem Swellin ng Inflam mmation off the tissuees borderin ng the airrway

A 26--year-old m man arriveed in the Em mergency D Departmen nt h having been n in a housse fire. His face and oral o cavity showed heeavy deposits of ccarbonaceo ous materia al. He was alert, able to speak in n a hoarse voice and was m moderatelyy tachypnoe eic. Ten miinutes lateer he complained of d difficulty b breathing, had h significant strido or and coulld not voca alise. Afterr a further ten t m minutes he was drowssy, obtund ded and in severe s resp piratory disstress. It was w d decided to intubate i th he patient aand this wa as achieved d only with h great diffficulty d due to almo ost complete airway o obstruction n secondarry to oedem ma and in nflammation of the epiglottis e an nd larynx caused c by thermal in njury. Brea athing d difficulties in burn vicctims frequ uently requ uire immed diate trach heal intubattion due to o rapidly developing d airway/glo ottic oedem ma. Seee the currrent PACT module on n Environm mental hazards. A sep parate mod dule on Bu urns Injuryy is in prep paration. Seee Task 4 Difficult D airrway algorrithms and d adjuncts to t managem ment. A Airway obsttruction is difficult to o describe but b has a characteristtic presenttation. N Noisy breath hing (on in nspiration ttermed strridor), poor expired aairflow, rettraction off soft tissuees, increased respirattory distreess and parradoxical ‘rrocking’ m movements of the thorrax and ab bdomen occcur. These resolve qu uickly if the e ob bstruction is removed d. In total airway obsstruction th here are noo sounds of o brreathing du ue to comp plete lack o of airflow through t the e larynx.

Wh hen possible e, obtain haands-on exp perience in a simulation n facility or arrange w with an anaesthesiology y colleague tto go to the anaestheticc room/recoovery ward. There yo ou will havee the opporttunity to praactise and become b com mpetent in aairway mano oeuvres (ccommonplace in this en nvironmentt) which willl prevent orr correct airrway obstru uction.

Q Q. What is s the diffe erence be etween str ridor and d broncho ospasm? A.. Stridor is the t term used to descriibe an inspiiratory noise, which sou unds simila ar to ‘w wheezing’. Itt is due to partial p upperr airway obstruction frrom any cau use e.g. fore eign bo ody/tumourr in airway or to condittions causin ng vocal corrd oedema oor paralysis. It is a veery significa ant clinical sign s and maay herald to otal obstructtion/respiraatory arrestt. Brronchospassm is predom minantly an n expiratory y ‘wheezing’’ sound assoociated with h brronchial narrrowing e.g. asthma, C COPD or ana aphylactoid reactions.

R Recognitio on of inju uries to a airway or r other str ructures Trrauma to the t head an nd neck maay have dirrect effectss on the aiirway. Fracctures or dislocation to the facia al skeleton n and m mandible may m cause im mmediate disruption n to the stru uctures of th he naso- an nd oropharrynx. Otherr complica ations may occur laterr [3]

Asseessment of the t airway should be repeated frequently f during resusscitation of th he trauma patient

Task 1. Asssessment of airway a

ass a result of o inflamma ation or so oft tissue sw welling and d bleeding in nto the airw way. Pulmo onary aspirration of blood or disslodged teeeth may occur. Po ostoperativve bleeding g after opeerations to the neck (tthyroid glaand, carotid, laarynx) mayy lead to co ompression n or displaccement of the t airwayy and subse equent diifficulty in intubation n. Direct in njury to thee larynx is rare but m may result in i diisruption of o the laryn ngeal mech hanism pro oducing pro ogressive h hoarsenesss and su ubcutaneou us emphyssema. Trach cheal intubation may make this situation worse w an nd, if attem mpted, requ uires greatt care and skill. s

In assessing a th he airway, allways recog gnise the po otential for ccervical spin ne in njuries. Inad dvertent mo ovement of tthe cervicall spine may occur durin ng airway m manoeuvres. This should be avoideed or at least minimised d by choosin ng the best teechnique an nd by approp priate execu ution. TH HINK Wha at risk facto ors for cervi cal spine in nstability can n you identtify?

Th he referencces below will w be help pful.

Daffner RH. Identifying patients att low risk for cervical sp pine injury: the Canad dian C-spin ne rule for raadiography.. JAMA 200 01; 286(15):: 1893–1894 4. No ab bstract availlable. PMID D 11597293 Am merican Co ollege of Surrgeons. ATL LS ® for Do octors Stude ent Manual.. 8th ed. 2008. pp. 63–65 5

R Recognitio on of ana atomic va ariations//abnorm malities D Difficulties in i maintaining or seccuring a pa atent airwa ay can often n be anticiipated byy thorough h inspection and inveestigation of o the anato omy of thee oropharyn nx, m maxilla, mandible, den ntition and d neck. It iss importan nt to realisee that whille some off these sign ns are visib ble, some aare only detectable by y investigattion. Th he followin ng anatomical featurees suggest airway diffficulty or d difficult in ntubation:         

Obessity Maxiillary progn nathia or p prominent upper inciisors Shortt muscularr neck and//or limited d neck flexiion or head d extension n (rheu umatoid arrthritis, ank kylosing sp pondilitis) Largee breasts e.g. in advaanced pregn nancy Acrom megaly High h arched pa alate (Marffan syndrom me) Orop pharyngeal infectionss and tumo ours Cystiic hygroma a Thyro o-mental distance: d m measured frrom the up pper edge oof the thyro oid [4]

Task 1. Asssessment of airway a

cartillage to the chin with the head fully fu extend ded. A distaance over 7 cm is usuallly associatted with eaasy intubattion. A disttance less tthan 6 cm may prediict a difficu ult intubatiion. Inability to open mo outh suggeests potenttial airway difficulty:        

Massseter musclle spasm (d dental abscess) Temp poro-mand dibular join nt dysfunction Scarrring – inclu uding postt radiothera apy fibrosiis Rheu umatoid arthritis Facia al burns Sclerroderma Trism mus Pierrre Robin sy yndrome: ccharacterissed by an unusually u ssmall mand dible (micrrognathia), posteriorr displacem ment or retrraction of tthe tongue e, upper airwa ay obstructtion. Cleft p palate pressent in the majority oof patients.

mobility/ab bnormalityy might su uggest a diffficult intubbation: Ceervical imm     

Preseence of cerv vical collarr Ankyylosis spondylitis Post radiothera apy fibrosiss Cerviical haema atomas (thyyroid or an nterior cerv vical surgeery) Klipp pel–Feil ab bnormalitiees of the ceervical spin ne.

Basic airwayy managem ment as weell as tracheeal intubattion may bee difficult or o im mpossible without w gre eat expertiise and/or special tecchniques. S Some of these faactors may be assesse ed using th he Mallamp pati or Wilson Scoress. Further details d arre availablee in the sou urces below w.

M Mort TC, Gab brielli A, Co oons TJ, Beh hringer EC. Airway Ma anagement. In: Gabriellli A, Layyon AJ, Yu M, editors. Civetta, Tay ylor and Kirrby’s Criticaal Care. 4th h ed. Ph hiladelphia:: Lippincottt Williams and a Wilkinss; 2009. ISB BN 978-07817-6869-6. pp. 519–556 M Mallampati SR, S Gatt SP,, Gugino LD D, Desai SP,, Waraksa B, B Freibergeer D, et al. A clinica al sign to prredict difficcult tracheall intubation n: a prospecctive study. Can Anaesth A Socc J 1985; 32 (4): 429–43 34. PMID 40 027773 W Wilson ME. Predicting P difficult d intu ubation. Br J Anaesth 1993; 1 71(3):: 333–334. No ab bstract availlable. PMID D 8398510 htttp://www.ffaces-cranio o.org

Su uch scores are of valu ue in everyy situation when there is time foor evaluation and to o choose th he techniqu ue of choicee for airwa ay managem ment. Otheer work, (rreferenced below) has highlightted that alll such assesssments arre useful bu ut not fo oolproof. When W airwa ay difficultyy occurs un nexpectedlly (an urgeent/emerge ency siituation), th he use of a difficult aairway algo orithm (Tassk 4) shoulld be mand datory.

[5]

Task 1. Asssessment of airway a

el-Ganzouri AR, A McCartthy RJ, Tum man KJ, Tan nck EN, Ivan nkovitch AD D. Preop perative airw way assessm ment: predicctive value of o a multivaariate risk index x. Anesth An nalg 1996; 8 82(6): 1197– –1204. PMID 8638791 ose DK, Coh hen MM. Th he airway: p problems an nd predictio ons in 18,50 00 patients. Ro Can J Anaesth 19 994; 41(5 Ptt 1): 372–38 83. PMID 8055603 Kaarkouti K, Rose R DK, Wigglesworth W h D, Cohen MM. Prediccting difficu ult intuba ation: a mu ultivariable aanalysis. Ca an J Anaesth h 2000; 47((8): 730–73 39. PMID D 10958088 8

P Protectiv ve reflex xes uard a pateent airway y and to preevent foreign Prrotective reeflexes exist to safegu m material enttering the lower l resp iratory tra act (pulmon nary aspiraation). The e upper aiirway sharees a comm mon pathwaay with thee upper gasstrointestin nal tract. These T reeflexes dep pend on the e proper fu unctioning of the epig glottis, falsse and true e vocal co ords and th he sensory supply to tthe mucou us membra ane of the p pharynx. Q Q. What cllinical sittuations/d diagnose es are asso ociated w with partial or to otal loss of o reflexe es protectting patie ents from pulmona ary aspira ation? A.. Any cause of:  Decreeased level of o conscioussness: intox xication, ove erdose, braiin injury, brrainstem dysfunction n, stroke, tu umour, dem myelination, polyneuritiis. 

Mech hanical (mottor) impairm ment of swa allowing: ph haryngeal tu umour, pha aryngeal pouch h, polyneuriitis.



Senso ory impairm ment of pharrynx/larynx x: local anae esthesia, poolyneuritis.

Paatients who can swalllow normaally have in ntact airwa ay reflexes.. Normal sp peech m makes absen nce of such h reflexes u unlikely bu ut not impo ossible. If a patient to olerates an n oropharyyngeal airw way (see latter) withou ut gagging then the p protective reflexes r arre either ab bsent or ob btunded. T The referen nce below will w yield fu urther deta ail on ph haryngeal and laryng geal reflexees if requirred.

Byyron J and Bailey JB, editors. e Heaad and Neck k Surgery – Otolaryngoology. 3rd ed. delphia: Lip ppincott Wiilliams and Wilkins; 20 001. ISBN: 0 0781729084 4. Philad pp. 48 85–491

Patiients with a decreaseed level of consciousn c ness (LOC)) should be e asssumed to have inade equate pro otective refflexes until proven oth therwise.

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Task 1. Asssessment of airway a

R Respiratory driv ve nt and pro otected airw way will faiil to ensure e adequatee oxygenatiion and Evven a paten exxcretion off carbon dioxide in th he absence of adequate respirattory drive. R Respiratoryy drive is co ontrolled b by the respiiratory cen ntre which acts to ma aintain pH H (in the CSF) C at 7.4. If arteriall pCO2 incrreases (for example bby rebreath hing of exxpired air containing c g CO2) this reduces pH H and resu ults in an in ncrease in minute vo olume – th he volume of o gas enteering and leeaving the lungs per minute – due d to sttimulation of the resp piratory ceentre. This reverses th he rise in C CO2 (negatiive feeedback). This T assum mes that inccreased resspiratory drive d produ uces an increase in n minute veentilation (increased ( d respiratorry rate and d/or tidal vo volume per brreath). Thiis may not occur if reespiratory mechanics m are disturrbed. he mechan nisms invollved in thee control off breathing g and comm mon factorrs Th w which influeence this sy ystem can be fully un nderstood by b readingg the PACT T m modules on Mechaniccal ventilatiion and Reespiratory failure. f Q Q. What fa actors inffluence m minute vollume in (a) a spon ntaneouslly br reathing patient with w multtiple fracttured ribs s and (b) the same e patient aftter initiattion of po ositive pre essure ve entilation n? olume of gass passing in nto/out of th he lungs perr A.. (a) Minutee volume is the total vo m minute, calcu ulated by re espiratory raate x tidal volume. v n this patien nt, both facttors will be iinfluenced by degree of o pain/anallgesia, respiiratory In deepression due to narcotics (reducee respiratorry rate) or otther drugs, mechanical effects off fractured ribs, r interco ostal spasm and underllying lung in njury (or prre-existing disease). d (b b) Mainly reespiratory ra ate and tidaal volume (v volume conttrolled) or iinspiratory prressure (preessure contrrolled) settiings on venttilator. Som metimes therre may be ad dditional minute ventillation due to o spontaneo ous respirattion by the p patient (see e ab bove).

Seee the PAC CT module on Mechan nical ventiilation (glo ossary). A An objectivee and wide ely accepted d measure of LOC is the Glasgoow Coma Scale. S A deecreased LOC L is due to widesprread depreession of ne euronal acttivity and, not su urprisinglyy, may be associated a w with depreession of th he respiratoory centre and heence reducced respira atory drive.. Opioids, sedatives s and a alcohol ol are poten nt reespiratory centre dep pressants. Seee the PAC CT module on Sedatio on and ana algesia.

O Opioid and non-opioid d analgesiccs in the IC CU. In: Waldmann C,, Soni N, Rhod des A, edito ors. Oxford d Desk Refference: Critical Care . Oxford: Oxforrd Universsity Press; 2 2008. ISBN N: 978-0-1199-22958 8-1. pp. 206 6– 207 V Ventilatory function and respiraatory drive can be assessed by loooking, listtening nd feeling. If a patien nt is breath hing sponta aneously, listening too the sound ds and an [7]

Task 1. Asssessment of airway a

feeeling air movement m while w lookking at the volume v and frequenccy of thoracic m movement gives g an im mpression o of airflow. This is the e initial clin nical techn nique fo or assessing g the ventiilatory funcction. It is quick, sim mple and eaasy but unrreliable ass a quantitative meassure of tidaal or minutte volume. O Observing th he nature of o the movvements off the thorax x/abdomen n and the reespiratory rate r is also o part of asssessing thee adequacy y of minutee ventilatio on, as is th he measureement of arrterial pCO O2 by blood d gas analy ysis. End-tiidal CO2 ca an often (b but not alw ways) be used as a reaal time mea asure of the adequacyy of minute veentilation. If respirattory drive/m minute ven ntilation iss inadequat ate, respirattory su upport, usu ually in the e form of p positive preessure venttilation shoould be insstituted.

In nspired oxygen concen ntration W When mana aging the airway, the aim is to produce p the e maximum m oxygen tension t po ossible in the t alveoli.. The balan nce betweeen oxygen supply s and d demand is i often un nfavourablly altered due d to imp paired card diorespirato ory functioon and incrreased m metabolic demands in n illness or after injurry. Therefore high insspired oxyg gen co oncentratio ons are req quired to saatisfy tissu ue oxygen demand, d prrevent tisssue hyypoxia and d to preven nt critical d de-saturatio ons. CT module on Respiraatory monitoring. Seee the PAC A cuffed tracheal tube represent s a sealed system s and d thus the oxygen co oncentratio on delivere ed to the tu ube will be the inspired concenttration. Co onversely, patients apparently a receiving 100% 1 oxyg gen via a faace-mask are in nspiring mu uch less e.g g. 40–60% % O2. When n breathing g oxygen th hrough a fa acem mask, entra ainment of room air aand dilution of the ox xygen conccentration occurs o du ue to manyy factors in ncluding th he rate of oxygen o flow w, the inspiiratory flow w rate an nd tidal volume gene erated by th he patient and the ea ase of ingreess of room m air arround the edges e (or through t ho oles) of the face-mask k. W When wishiing to deliv ver the maxximum insspired oxyg gen concen ntration to a paatient usin ng a face-m mask, the m mask should d be close fitting f with h a reservo oir bag an nd no laterral opening gs. Oxygen n flow shou uld be 15 l/m min. If 100 0% oxygen n is deelivered to o such a sysstem, the p patient willl be inspiring approxiimately 80 0–85% oxxygen. Usin ng an oxyg gen reservo oir is also necessary n when w a pattient is ven ntilated ussing a bag--valve-massk if entrain nment of room r air (a and dilution n of the inspired oxxygen conccentration)) is to be avvoided. Thee oxygen mask m used aand the speeed of oxyg gen flow arre importan nt faactors in deetermining g the conceentration of o oxygen delivered d too the patien nt’s aiirway. Id dentificattion of sig gns of hy ypoxaemiia H Hypoxaemia a, defined as reduced d partial prressure of oxygen o in arrterial bloo od due to in nadequatee oxygenatiion, may re esult in (ttissue) hyp poxia and, potentially p y, cellular damage/de d eath.

[8]

16.1 g/dl g = 10 mmol/l

Task 1. Asssessment of airway a

H Hypoxaemia a may causse widesprread bluish h discoloura ation of th he mucous m membraness and nail-b beds termeed central cyanosis. c This T is due to the pressence off deoxy-haemoglobin n in a conceentration of o at least 5 g/dl. Hyp poxaemia may m leead to agita ation, confu usion, drow wsiness as well as sig gns of symp pathetic ovveractivityy and respirratory distrress. If nott corrected d rapidly, itt may lead to caardiac arreest, irreverssible cereb bral injury, organ dysfunction an and death. Seee the PAC CT module on Respiraatory failurre. N Note that a patient p witth significaant anaemiia may nev ver exhibit cyanosis, while w allive, despitte severe hy ypoxia. Wiith a low to otal haemo oglobin it m may not be po ossible to have h as mu uch as 5 g/ dl in the deoxygenate ed form. Id dentificattion of dy yspnoea D Dyspnoea, breathlessn b ness, respirratory disttress and re espiratory difficulty are a cllosely relatted. Breath hlessness caan be conssidered as a subjectivve judgmen nt – a syymptom th hat may be defined ass an inapprropriate relationship between reespiratory work w and total t body work. The other term ms are morre objective e and m may be pressent even when w a patiient deniess being bre eathless. Cllinically siignificant dyspnoea d may m be diffficult to detect especiially in patiients with preexxisting resp piratory diisease and when it is evolving sllowly. Q Q. What ar re the clin nical sign ns of dysp pnoea? A..        

Tachyypnoea Inabillity to speak k more than n a few word ds between breaths Sweatting/tachyccardia/hypeertension Cardiiac dysrhyth hmia Agitattion/refusa al to lie down n Use of o accessory muscles Retra action of sup praclaviculaar/suprasternal/interco ostal tissuess Pursin ng of lips/n nasal flaringg.

Asssess six hosp pital in-pattients with chronic c obsttructive pullmonary dissease for siggns of dysp pnoea and grrade their sseverity of distress. d

Thee onset of hypoxaemi h ia and resp piratory diffficulty mayy be gradu ual and iss sometimees unsuspected until ccardioresp piratory arrrest is imm minent. Bew ware of paatients who o appear confused, d disorientateed or ‘drun nk’ – particcularly if su ubsequentlly they beccome ‘quiett’.

[9]

Task 2. Aiirway interven ntions

2. AIIRWAY Y INTER RVENTIO ONS Th he inabilityy to establiish a defin itive airwa ay may be the t result oof failure to o op ptimise clin nical conditions wheen perform ming airway y manoeuvrres. Inexpe erience an nd/or lack of skill on the part o of the practtitioner and d lack of skkilled assisstance arre importa ant factors in i scenario os in which h airway prroblems arre reported d. Co ommon errrors includ de:  Poor patient po ositioning  Failu ure to ensurre approprriate assisttance  Faultty light sou urce in laryyngoscope//no alterna ative scopee  Failu ure to use a longer blaade in apprropriate pa atients  Use of o inapprop priate trach heal tube (size ( or sha ape)  Lack of immediiate availab bility of airrway adjun ncts.

Saagarin MJ, Barton B ED, Chng YM, W Walls RM. National N Em mergency A Airway Registry Investig gators. Airw way managem ment by US S and Canad dian emerg gency mediccine residen nts: a multicenter analy ysis of moree than 6,00 00 endottracheal intu ubation atteempts. Ann n Emerg Med 2005; 46((4): 328– 336. PMID P 16187 7466 Klluger MT, Short S TG. Asspiration du uring anaessthesia: a review of 1333 cases from m the Au ustralian An naesthetic IIncident Mo onitoring Sttudy (AIMSS). Anaessthesia 1999 9; 54(1): 19– –26. PMID 10209365 M Mayo PH, Ha ackney JE, Mueck M JT, R Ribaudo V, Schneider RF. Achieviing house staff competence c e in emergen ncy airway managemen nt: results oof a teaching g progrram using a computerizzed patient simulator. Crit C Care M Med 2004; 32(12 2): 2422–24 427. PMID 115599146 Klluger MT, Bullock B MF.. Recovery rroom incideents: a revie ew of 419 rep eports from the An naesthetic Incident I Mo onitoring Sttudy (AIMS). Anaestheesia 2002; 57(11)): 1060–106 66. PMID 12 2392453 Ro obbertze R,, Posner KL L, Domino K KB. Closed claims c revie ew of anesth hesia for proceedures outsiide the operrating room m. Curr Opin n Anaesthessiol 2006; 19(4):: 436–442. PMID 1682 29728

P Patient positioni p ing

, you must ask: Wh hen considerring and peerforming an ny airway manoeuvres, m a ‘A Am I sure th hat this patie ent has a staable cervica al spine’. If the t answer is negative,, you m must use man nual in-line e immobilis ation of thee cervical sp pine during tthe manoeu uvre wh which will require the he elp of a seco ond person.. This is mo ost relevant to patients who haave sustaineed significan nt trauma b but may also o be importtant in patieents with se evere ceervical spinee pathology y e.g. rheum matoid arthritis, severe osteoporosiis.

Co orrect patiient positio oning is esssential to facilitate f su uccessful aairway m managemen nt. Elevatin ng the head d 7–10 cm with a pillow under tthe occiput and exxtending th he atlanto--occipital jo oint should d align the oral, pharryngeal, an nd [10]

Task 2. Aiirway interven ntions

laaryngeal ax xes to proviide the besst straight line l from lips l to glotttis (sniffing po osition). O2

Preparat ion 7 -1 1 0 cm

© Kathy Ma ak 2004

M Mort TC, Gab brielli A, Co oons TJ, Beh hringer EC. Airway Ma anagement. In: Gabriellli A, Layyon AJ, Yu M, editors. Civetta, Tay ylor and Kirrby’s Criticaal Care. 4th h ed. Ph hiladelphia:: Lippincottt Williams and a Wilkinss; 2009. ISB BN 978-07817-6869-6. pp. 519–556 Laavery GG, McCloskey M BV. B The diffficult airway y in adult crritical care. Crit Care Med 2008; 2 36(7)): 2163–21773. PMID 18 8552680

C Clearing the airw way ng normallly may be assumed a to o have a cllear airway y. The Paatients who are talkin in nability to speak s norm mally, partiicularly in an obtund ded patientt, may be due d to aiirway obstrruction by the tonguee or by material – liq quid (salivaa, blood, ga astric co ontents) orr solid (teeth, broken n dentures, food) – in n the posterrior oropharynx an nd nasopharynx. Children mayy obstruct their airway y with sweeets or sma all toys in n the mouth h or furthe er down th e airway. s should be cleared un nder directt vision witth a laryngoscope Iff possible, secretions ussing a sucttion device. If oral sucction is no ot possible, the nasop pharyngeal route sh hould be ussed. The finger sweep p should be reserved for patien nts withoutt an in ntact gag reeflex. A chiild was adm mitted to th he Resusciitation Rooom after a road r trraffic accid dent. The child c had b been a back k seat passe enger and w was deeply y cy cyanosed an nd had obsstructed brreathing. Use U of the triple airwaay manoeu uvre (see b below), succtioning of the pharyn nx and an oropharyn o geal airway ay had no b beneficial effect. e At la aryngoscop py the voca al cords werre easily seeen but an o orotracheall tube could d not be in nserted into o the trach hea. Duringg attempts to p perform a tracheostom t my, the chiild suffered d a cardiacc arrest and d could nott be reesuscitated d. At post-m mortem a small plasttic toy wass found lod dged in the airway aat the level of the cricoid ring. Thee indication ns and con ntraindicatiions for the e various aairway m manoeuvress and assocciated equiipment/tecchniques are a discusseed briefly below. b

[11]

Task 2. Aiirway interven ntions

T Triple air rway ma anoeuvrre his manoeuvre is ofte en useful in n situation ns where maintaining m g a patent airway a Th ussing neck extension e alone a has ffailed or is not recom mmended, p particularly y in the ob btunded pa atient. The e triple airw way manoeeuvre emplloys head ttilt (neck exxtension), jaw j thrust and mouth h opening.. However,, it will likeely be inefffective w when airwayy obstructiion is causeed by a forreign body.. Th he operato or should sttand behin nd and abo ove the patiient's head d and   

Exten nd the neck k by placin ng the hand ds on eithe er side of th he mandible Eleva ate the man ndible with h the fingers of both hands, h thu us lifting th he base of thee tongue aw way from tthe glottic opening Open n the mouth h with the thumbs orr forefingers.

©Janet Fon ng 2011; htttp://www.aicc.cuhk.edu.h hk/web8/Hi% %20res/Triplle%20manoeeuvre3.jpg

Do not use necck extension n in situatio ons of actual or potentiial cervical spine s in njury. Both the t jaw thru ust and chin n lift may allso cause disstraction off cervical sp pine in njuries.

A Artificiall airway y Thee beneficiall effect of aany or all elements e off the triple airway m manoeuvre may be losst if discon ntinued since the man ndible or toongue may y fall baack and (ag gain) obstrruct the airrway. The insertion i of o an artificcial airway y beetween thee tongue an nd the postterior pharryngeal wall should p prevent this. O Oropharyngeal air rway A An oropharyyngeal airw way is the m most comm monly used d artificial aairway, as it is reelatively sim mple to inssert and sh hould avoid d many of the t problem ms associa ated w with the nassopharynge eal airway (see below w). It is ofte en used to facilitate oxxygenation n/ventilatio on prior to o tracheal intubation. [12]

Task 2. Aiirway interven ntions

Q Q. In whatt clinical situation s ns would an a oropharyngeal airway m mitigate upper u airw way obstrruction? A.. The oroph haryngeal airway is of ggreatest ben nefit in the temporary m managemen nt of up pper airwayy obstruction due to losss of tone in n the muscu ulature assocciated with the aiirway. This is most com mmonly duee to decreased level of consciousne c ess, potentia ally due to o a myriad of o causes inccluding acu ute hypoxia or o hypercarrbia, drug ovverdose/inttoxication, induction off/recovery from f anaestthesia or carrdiorespirattory arrrest.

n adults, th he oropharyngeal airw way should d be inserte ed with thee convex siide In to owards thee tongue an nd then rottated throu ugh 180 deg grees. Caree must be taken t to o avoid pusshing the to ongue postteriorly an nd worsenin ng the obsttruction.

© Janet Fong 2010. Repro oduced from www.aic.cuh hk.edu.hk/web8. htttp://www.aiic.cuhk.edu.h hk/web8/Hii%20res/orop pharyngeal% %201_CMYK K.jpg

ontraindiccations to the use of aan oropharryngeal airw way includ de (all relattive): Co  

Inabiility to tole erate oroph haryngeal airway a (gag gging/vom miting) Fragiile dentitio on – includ ding presen nce of prosthetics.

Co omplicatio ons of the oropharyng o geal airway y:     

ging or coughing Gagg Vomiiting and aspiration a Laryn ngospasm Traum ma (teeth, mucosa, to ongue etc)) Worssening airw way obstru ction o Pushing tongue po osteriorly ent of tip o of airway in n vallecula. o Lodgeme

N Nasophar ryngeal airway Th he nasopharyngeal airway has tthe same indicationss as the oroopharyngea al aiirway but is i usually more m easilyy tolerated. However,, insertion is co ontraindica ated in: [13]

Task 2. Airway interventions

  

Adults with blocked or narrow nasal passages Patients with fractures of the mid-face or base of skull When bleeding from the nasal cavity would be disastrous.

Complications of the nasopharyngeal airway:     

Trauma to nasal turbinates/nasal mucosa Bleeding from nasal cavity (especially into pharynx) Laryngospasm Gagging or coughing (less likely than with oropharyngeal airway) Vomiting and aspiration.

Any artificial airway should be looked on as a temporary adjunct – to be replaced with a more secure airway if the patient fails to improve to the point where they no longer need an artificial airway. Similarly such airways should not be used in association with any form of prolonged positive pressure ventilation, although they may be used to facilitate bag-mask ventilation as a preparation for tracheal intubation.

Oxygenation and ventilation Oxygenation usually requires movement of (inspired) gas down a patent airway to the alveoli. Once a patent airway is achieved, such flow may either be achieved by patient spontaneous effort or by assisted ventilation. Variable flow face-mask If the patient is breathing spontaneously, oxygen may be supplied by either a face-mask or a bag-valve-mask device. Depending on the patient’s tidal volume, peak flow rate and entrainment of ambient air, 100% O2 with a 8–12 l.min-1 flow through a simple face-mask should result in an inspired O2 concentration of 40–60%. If a reservoir bag is attached to the mask an inspired oxygen concentration of over 80% may be achieved dependent on the three factors mentioned above. Entrainment of ambient air is minimised by a close fitting mask or a mask which seals the mouth and nose from the ambient air. Manual ventilation using a mask If the patient’s spontaneous (negative pressure) breathing is either absent or inadequate it should be augmented or replaced with positive pressure ventilation. This positive pressure can be generated manually, using a bag and mask (as part of an anaesthetic circuit/breathing system) or a bag-valve-mask. A bag-valve-mask (also known as a BVM or e.g Ambu® bag) is a hand-held device used to provide positive pressure ventilation to a patient who is not breathing or who is breathing inadequately. Manual ventilation using a mask and anaesthetic circuit or a BVM is usually only a short-term measure in urgent situations and/or as a preparation for tracheal intubation. The airway should first be cleared using the manoeuvres described earlier. Failure to clear the [14]

Task 2. Aiirway interven ntions

aiirway will produce p in nadequate vventilation n and poten ntial gastriic distensio on and reegurgitatio on. Ventilation with a massk requiress a tight fitt between mask m and V faace. This ca an be best achieved a b by placemeent of the mask m on thee faace by hold ding it with h the thumb b and first finger (C-g grip) and pu ulling the mandible m upward u tow wards the mask m with the other th hree fingers. Excessiv ve pressuree on the ma ask may either lead tto fleexion of th he cervical spine with h subsequen nt airway obstruction o n orr tilt of thee mask with h lateral leaakage, or both. b If the ere are prroblems seealing the face-mask f tto the facee with one hand, h use tw wo hands while w a seco ond person n squeezes the reserv voir bag.

A second person n can be of help

Q Q. What co onditions s are likelly to mak ke manual ventilattion with a bag an nd mask or a BVM M difficultt? A..      

Anato omical causes such as rreduced/no dentition, presence p off large jaw or o beard ded Obesiity Poolin ng of blood or secretion ns in the ph harynx Maxilllofacial and d nasal trau uma or tumo ours Infecttions and in nflammatory ry disorders Faciall burns.

Q Q. How wo ould you maintain n oxygena ation in an n unconsscious or an naesthetiised patie ent, who ccannot be e manuallly ventila ated using a m mask desp pite two person p ven ntilation and inse ertion of a an or ropharyn ngeal airw way? Wha at sequen nce would d you follo ow? optimal possitioning and intubate iif possible. If A.. Perform one laryngosscopy with o in ntubation is not possiblle, insert a llaryngeal mask m airway and attemp pt ventilatio on. If sttill ineffectivve, waken th he patient iff this is posssible and se ecure the air irway using an aw wake techniique. If unab ble to ventillate or wakeen the patie ent (as is likkely in the un nconscious critically illl patient), a surgical airrway will be e required.

Ap Apnoeic ox xygenatiion Ap Apnoeic oxyygenation is i oxygenattion of blood in the pulmonary p y capillariess by m merely provviding a con ntinuous fllow of 100% oxygen via v a narroow catheterr into [15]

Task 2. Aiirway interven ntions

th he trachea with free egress e of gaas around the t cathete er (open syystem). It will w not reesult in thee clearance e of carbon dioxide. This T may alllow 20–30 0 minutes of oxxygenation n without any a mass m movement of o gas (‘apn noea’). Q Q. List two o potentia al indicattions for apnoeic a oxygenati o ion in critical ca are. A..   

As a pre-emptive p e measure aat intubation ns in situatiions with prresumed diffficult airwa ay. In thee ‘cannot intubate–can nnot ventilatte’ scenario – usually vvia a needle cricotthyroidotom my. Durin ng the apnoea test when n attemptin ng to establiish the diaggnosis of bra ain-stem death h.

Q Q. What ar re the con ntraindiccations to o apnoeic oxygenattion? xygenation is contraind dicated in patients p with h establisheed or potenttially A.. Apnoeic ox raaised intracrranial presssure due to tthe detrimeental effectss of the resu ulting hyperrcarbia. T module on n Traumaticc brain inju ury. Seee the PACT

M Mort TC, Gab brielli A, Co oons TJ, Beh hringer EC. Airway Ma anagement. In: Gabriellli A, Layyon AJ, Yu M, editors. Civetta, Tay ylor and Kirrby’s Criticaal Care. 4th h ed. Ph hiladelphia:: Lippincottt Williams and a Wilkinss; 2009. ISB BN 978-07817-6869-6. pp. 519–556

T Tracheall intubattion M Main indica ations for trracheal inttubation in nclude:        

Inabiility to obta ain/maintaain an uno obstructed airway by other mea ans Long g-term prev vention of airway obsstruction Proteecting the airway a (lacck of protecctive reflex xes) Inadeequate ven ntilation orr oxygenatiion To fa acilitate possitive presssure ventillation To fa acilitate bro onchopulm monary toillet Life-tthreatenin ng haemodyynamic insstability Comb bativeness that preveents emerg gency diagn nostic stud dies (need for f heavyy sedation)).

W When tracheal intubattion is diffi ficult, whetther anticip pated or noot, the choiice of siimple manoeuvres an nd/or piecees of equip pment can improve i th he chancess of su uccess. Theese are desscribed witthin Task 4. 4

[16]

Task 2. Aiirway interven ntions

O Orotrache eal intuba ation O Orotracheall intubation n is the staandard and d most relia able teechnique fo or those prractised in direct lary yngoscopy. Normally,, an nalgosedattion and ne euromuscu ular blocka ade are neccessary for th his procedu ure. There are no abssolute conttraindicatio ons allthough thee condition ns listed un nder ‘Reco ognition of anatomicaal vaariations/a abnormalitties’ in Tas k 1 requiree careful pllanning or th he use of allternative strategies: s

There T is no subsstitute for ‘hands ‘ on’ practice p of tracheal in ntubation

Th he basic prrinciples sh hould be u nderstood d prior to atttempting in ntubation. Th he conductt of endotrracheal intu ubation is as follows:: P Prepare an nd assess s the patie ent P Prepare an nd test th he equipm ment          

Rang ge of trache eal tubes lu ubricated and a cuffs te ested for p atency o Adult fem male 7.0–8 8.0 mm intternal diam meter Conssider a size 8 or ale 7.5–9.0 0 mm interrnal diame eter o Adult ma larger tube t in patieents otracheal tu ube introd ducers Endo who you believe may m Syrin nge for infla ating the ccuff of the endotrache e eal tube need bronchoscopy at a Rang ge of laryng goscopes in ncluding sp pecialised blades b aller later stage. Sma tubess will not alllow and handles. h Ch heck batterry and bulb b function satisfacttory passag ge of Funcctioning suction systeem a bronchosc cope Apprropriate an naesthetic aand resuscitation dru ugs Bite protection p Fixattion (tape, tie) Facilities for po ositive presssure ventiilation of th he lungs w with oxygen n Use of o personall protectivee equipment as appro opriate.

Theere is a tren nd towardss using sma aller sized tubes due to some ev vidence th hat it may reduce r airw way traum ma. Howeveer, narrowe er tubes inccrease worrk of sp pontaneous breathing g and beco ome narrow wed or bloccked by seccretions more m eaasily. O Optimal pa atient positioning g (see earlieer) Preoxygen nate the pa atient with h 100% oxy ygen for 3– –5 minutess if possible e. P A Administe er drugs In ntravenouss anaesthessia inducti on agent will w depend d on the haaemodynam mic sttability of the t patientt.   

Propofol 0.5–2 mg/kg Thiop pentone (T Thiopental)) 1–5 mg/k kg Mida azolam 0.05–0.1 mg//kg. [17]

Task 2. Aiirway interven ntions

Al Although lesss popular than in th he past, kettamine and d etomidatee are also used u by so ome practitioners in situations with haem modynamicc comprom mise. N Neuromuscu ular blocka ade may bee achieved with:     

Suxamethonium m (succinyylcholine) 1–2 1 mg/kg for rapid ssequence Atraccurium 0.3 3–0.5 mg/k kg Vecuronium 0.05–0.1 mgg/kg Rocu uronium 0.6–0.9 mg//kg Rocu uronium 0.9–1.2 mg//kg has beeen advocated as a subbstitute forr suxam methonium m.

Q Q. What ar re (a) the e benefitss and (b) the t disadvantagess of using su uxametho onium (su uccinylch holine)? A.. (a)   (b b)         

Rapidly pro oduces exceellent intuba ating condittions. N Normally very short accting. Ca ardiac arrhy ythmias (brradycardia, tachycardia a) H Hypertension n H Hyperkalaem mia H Histamine lib beration M Myalgia In ncreased inttraoccular, iintragastricc & intracran nial pressurre Trrismus Prrolonged ne euromuscullar blockadee (abnormality of succiinyl choline esterase) Trrigger for malignant m hyyperthermia a

In patients p with neurom muscular diisorders, e..g. Guillain n–Barré, se evere hyyperkalaem mia may de evelop lead ding to card diac arrestt and death h. Seee the follo owing referrences for m more inforrmation.

Feeneck RO, Cook C JH. Fa ailure of diaazepam to prevent p the suxamethon s niuminducced rise in in ntra-ocular pressure. Anaesthesia A 1983; 38(22): 120–127.. PMID D 6829877 Laavery GG, McGalliard M JN, J Mirakh hur RK, Shep pherd WF. The T effects of atracu urium on in ntraocular p pressure durring steady state anaessthesia and rapid sequence in nduction: a comparison with succcinylcholinee. Can Anaessth Soc J 19 986; 33(4): 4 437–442. PMID P 37556 640

Perform la aryngosco opy P  

Hold d the laryng goscope in your left hand h near the t junctioon of the ha andle and blade. b Inserrt the blade e along thee right sidee of the mouth, displaacing the to ongue to thee left. [18]

Task 2. Aiirway interven ntions

 

     

Movee blade to midline. m If usiing a Macin ntosh blad de, direct th he tip of the blade intto vallecula a between the epiglottis and d the base of the tong gue. Lift laaryngoscop pe ards and upwards in the directiion of the handle h of tthe laryngo oscope forwa to (in ndirectly) elevate e the epiglottis.. This shou uld expose tthe glottis. If usiing a straig ght blade (ee.g. Miller)), place the e tip of the blade belo ow the epiglottis and liift as descrribed abovee. This willl (directly)) elevate th he epiglottis and should reveeal the glotttic opening. Avoid d angulatio on of the laaryngoscop pe and usin ng the teeth h as a fulcrrum. Pass the tracheal tube sm moothly into o the trach hea until th he cuff is se een to pass 2–3 cm be eyond the ccords. Inflatte the cuff.. Confi firm trache eal tube possition. Assesss cuff presssure.

© Janet Fong 2010. Repro oduced from www.aic.cuh hk.edu.hk/web8

C Choice of laryngosc l cope blad de he most wiidely used blade is th he Macinto osh. Often size s 3 is ussed as the default d Th fo or adult pattients. Use e of the biggger size 4 blade b has been b shown wn to be an ad dvantage in n visualisin ng the laryynx. Other blades, b forr example, McCoy (a hinged bllade tip, co ontrolled by a lever on n the hand dle), may be b advantaggeous in ce ertain siituations, particularly p y where theere is a neeed to main ntain minim mal cervica al spine m movement or o to reducce the stresss responsee to intubation. The u use of straiight bllades or sp pecialist sco opes may b be of use in n specific situations iff the opera ator has prrevious exp perience with w these in nstrumentts. Adjunctts and speccialised eq quipment required r fo or managin ng the diffiicult or abn normal airw way are disscussed in n Task 4 [19]

Task 2. Aiirway interven ntions

M McCoy EP, Mirakhur M RK K. The leverring laryngo oscope. Ana aesthesia 199 93; 48(6): 516–5 519. PMID 8292132 8 M McCoy EP, Mirakhur M RK K, Rafferty C C, Bunting H, Austin BA. B A compaarison of the forcess exerted du uring larynggoscopy. Th he Macintosh h versus thee McCoy blade. Anaesthessia 1996; 51((10): 912–9 915. PMID 8984862 8 Ko onishi A, Sa akai T, Nish hiyama T, H Higashizawa a T, Bito H. Cervical C spiine movement durin ng orotracheeal intubatio on using the e McCoy larryngoscope he Macintossh and the Miller M laryn ngoscopes. M Masui 1997; compared with th P 9028 8096 46(1):: 124–127. PMID N Nishiyama T, Higashizaw wa T, Bito H H, Konishi A, A Sakai T. Which W laryn ngoscope iss m stressfu ul in laryngo oscopy; Maccintosh, Milller, or McC Coy? Masui the most 1997; 46(11): 1519–1524. PM MID 940414 40 M MacQuarrie K, K Hung OR R, Law JA. T Tracheal inttubation using Bullard d laryng goscope for patients wiith a simula ated difficullt airway. Caan J Anaestth 1999; 46(8): 760 0–765. PMID D 10451135 5

N Nasotrach heal intub bation N Nasotrachea al intubatio on presentts several of o the problems assocciated with h the naasopharyn ngeal airwa ay and is ussed when th here are re elative conttraindicatiions to th he oral route. It may be b perform med by both h blind tecchniques an nd under direct d viision. It ma ay be perfo ormed eith her under general g ana aesthesia oor in the aw wake paatient with h appropria ate local an naesthesia.. A nasotra acheal tubee is usually y better to olerated byy ICU patie ents than a orotracheal tube butt is no longger favoure ed in m many health h systems due d to worrries about suboptima al tracheobbronchial toilet t an nd reduced d drainage from the p paranasal sinuses. s M May be usefful in:   

Patieent with short, thick n neck Jaw clenching c To maintain m miinimal necck movemeent.

ontraindiccations: Co   

Nasa al fractures Mid-face instab bility Base of skull fra actures.

P Prepare an nd assess s the patie ent   

Use a nasal deccongestant such as ph henylephrine or xylom metazoline e to reducce bleeding g. Exam mine each nostril n for p patency an nd deformiity. Choosee the most patent nostrril and estim mate the s ize of trach heal tube required. r T This will be e smalller than th hat required d for the orral intubattion. For nasal n intub bation perfo ormed und der generall anaesthessia (either as a blind d procedure e or underr direct visiion – see below), the patient is usually [20]

Task 2. Aiirway interven ntions



in thee same possition as th hat used forr intubatio on via the ooral route. Mostt nasal intu ubations peerformed due d to conccerns regarrding difficcult airwa ay/intubation are don ne with thee patient awake and ssitting up to t facilitate placem ment.

B Blind naso otracheall intubatio on     

The patient p sho ould be breeathing spo ontaneouslly. Lubricate the trracheal tub be well. Inserrt the trach heal tube in nto the nosstril with th he concavitty forward d and the bevel b directted laterallly. While passing the t tube do ownwards listen to au udible breaath soundss throu ugh the tub be. By genttly rotating g the tube, maximum m sound inttensity shoulld be achie eved. From m there, adv vance furth her. On en ntering the trachea, brreath soun nds throu ugh the tra acheal tubee and possiible coughiing may ind dicate succcessful posittioning.

Bllind nasotrracheal inttubation caan be time consuming and is noot suitable for raapidly desa aturating patients, p fo r example patients with w ARDS.. Do not force the tu ube as this could causse bleedingg. ntubation D Direct visiion nasotracheal in n    

Gentlly advance e the tube tthrough the nose as above. a Perfo orm laryng goscopy. When n the tube can be visu ualised in the t pharyn nx advancee under dirrect vision n into the trachea. t If it does d not prrogress, (M Magill’s) forrceps may be used too direct the e tip of the tu ube.

Avo oid touching g the cuff w with the forcceps as this may m damagge the cuff and a reesult in cufff leak and in neffective po ositive presssure ventila ation.

F Fibre opttic intub bation Aw Awake fibree optic intu ubation is th he techniq que of choicce with an informed, prrepared pa atient and a trained o operator wiith appropriate equip pment. The e teechnique en nsures tha at spontaneeous respirration and upper airw way tone ca an be m maintained.. Fiibre optic intubation i is particullarly usefu ul in many clinical c sceenarios:     

Poor mouth opening Abno ormal anatomy Previious difficu ult intubatiion Difficcult laryngoscopy of a normal la arynx Deterrmining th he nature aand extent of patholog gy [21]

Task 2. Airway interventions

    

Correct positioning of single and double lumen tracheal tubes Avoidance of dental damage in high-risk patient Minimising neck movement Direct laryngeal trauma Difficult laryngoscopy of a normal larynx.

It may not be useful or appropriate for:   

Open trauma of the upper airway (gross blood soiling) Obstruction below the cords A narrow glottic opening easily visible with direct laryngoscopy.

Contraindications (All relative) 

Respiratory: o Laryngeal obstruction o Severe hypoxaemia o Worsening hypercarbia o Severe asthma/bronchospasm o Pulmonary hypertension



Haematological: o Thrombocytopenia o Coagulopathy

Advantages of fibre optic intubation       

Flexibility to manoeuvre through the most difficult airway pathology Permits immediate visual confirmation of tube position Allows instillation of local anaesthetic and oxygen via the working channel Can be used in all age groups Facilitates (and facilitated by) the use of other devices Success rate is very high Most useful back up plan.

Conduct of fibre optic intubation Adequate psychological preparation is essential. Numerous sedation agents have been evaluated, including benzodiazepines, opioids such as alfentanil or remifentanil, and intravenous anaesthetic agents such as (low-dose) propofol infusion. Care must be taken not to overdose the patient and to maintain spontaneous respiration throughout. Supplemental oxygen should be provided, usually through the contralateral nostril. A nasal decongestant such as phenylephrine or xylometazoline to reduce bleeding will be useful particularly when using topical lignocaine. Topical anaesthesia Topical anaesthetic agents include lignocaine (lidocaine) or cocaine. Cocaine will produce vasoconstriction but has been associated with myocardial [22]

Task 2. Aiirway interven ntions

isschaemia. Nebulised N lignocaine l e can be useed but may y result in h high blood d liggnocaine leevels, coug ghing, and bronchosp pasm. Anae esthesia off the vocal cords an nd upper trrachea is usually u pro ovided by a ‘spray as you y go’ tech chnique usiing 2% liggnocaine. Another A po otential tecchnique is superior la aryngeal an nd recurre ent laaryngeal neerve blocka ade. P Preparatio on     

Placee tracheal tube t on fib brescope an nd ensure free f movem ment Tape tracheal tu ube lightlyy to fibrescope ent of fibresscope tip Check moveme Check orientatiion of cameera Reasssure patien nt.

Passage off fibresco ope and trracheal tu ube P                

Hold d fibrescope e aloft and d straight Inserrt into nasa al passage Smoo othly pass through naasopharyn nx Ask patient p to stick s out to ongue Gentlly suction secretions Identtify epiglotttis Slowlly advance e towards eepiglottis If vieew lost, witthdraw 1–2 2 cm Smoo othly pass through vo ocal cords (turn may be requireed) Identtify trachea al rings Adva ance until carina c visib ble Reasssure patien nt – advan nce tube disstally Ensu ure carina remains r vissible – no endobroncchial intub ation Ask assistant a to o hold trach heal tube Smoo othly remo ove fibresco ope Reasssure patien nt.

Laavery GG, McCloskey M BV. B The diffficult airway y in adult crritical care. Crit Care Med 2008; 2 36(7)): 2163–21773. PMID 18 8552680 Ovvassapian A. A Fibereopttic Endosco opy and the Difficult Aiirway. 2nd eed. Philad delphia: Lip ppincott-Raaven; 1996. ISBN: 07811702720 Po opat M. Pra actical Fibre eoptic Intub bation. Oxfo ord: Butterw worth-Heineemann; 2001.. ISBN: 0750644966. p p. 82 Beenumof JL, editor. Airw way Managgement: Prin nciples and Practice. Stt Louis: Mosb by; 1996. ISB BN: 081510 06254 Ko oerner IP, Brambrink B AM. A Fiberooptic techniq ques. Best Pract P Res Cllin Anaessthesiol 200 05; 19(4): 6 11–621. PM MID 16408537 Reeasoner DK K, Warner DS, D Todd MM M, Hunt SW W, Kirchner J. A compaarison of anesth hetic techniiques for aw wake intuba ation in neurosurgical p patients. J Neuro osurg Anestthesiol 19955; 7(2): 94–99. PMID 7772974 7

[23]

Task 2. Airway interventions

Graham DR, Hay JG, Clague J, Nisar M, Earis JE. Comparison of three different methods used to achieve local anesthesia for fiberoptic bronchoscopy. Chest 1992; 102(3): 704–707. PMID 1516390

Laryngeal mask airway The laryngeal mask airway (LMA) consists of a small mask at the end of a hollow plastic tube. It is placed ‘blindly’ in the lower pharynx. The laryngeal mask airway sits obliquely over the laryngeal inlet, with the (distal) tip of the mask sitting at the entrance to the upper oesophagus (posteriorly) and the base of the mask at the base of the tongue (anteriorly). The LMA does not protect the airway from aspiration but, if well positioned, positive pressure ventilation (low/moderate pressure) is possible. The LMA has a role in reducing the number of airway catastrophes. Indications for use of an LMA include:   

Conduit for a flexible bronchoscope Within the difficult airway algorithm Alternative to (i) oropharyngeal airway and mask and (ii) tracheal intubation in selected surgical procedures – rarely appropriate in critical care (see disadvantages below).

Advantages include:      

Often no more problematic to insert in patients with difficult airways Relatively easy to become competent in use with limited training Ventilation may be possible using gentle positive pressure May be used for intubation once oxygenation has been achieved Will facilitate passage of tube or fiberscope May help avoid catastrophic outcome in difficult airway scenario.

Contraindications:    

Lack of training and experience Patients with an active gag reflex Foreign body airway obstruction Severe oropharyngeal trauma.

Disadvantages include:     

The airway is not protected from aspiration It may move during use and cause airway obstruction It does not allow high airway pressures (ventilation with poor chest/lung compliance) to be generated in the airways May be dangerous in supraglottic, glottic and infraglottic obstruction Does not always provide an adequate airway.

[24]

Task 2. Aiirway interven ntions

Beenumof JL. Laryngeal mask airwaay and the ASA A difficultt airway alggorithm. Anestthesiology 1996; 84(3):: 686–699. Review. No o abstract avvailable. PMID D 8659797 Feerson DZ, Rosenblatt R WH, W Johanssen MJ, Osb born I, Ovasssapian A. U Use of the intuba ating LMA--Fastrach in n 254 patien nts with diffficult-to-maanage airwa ays. Anesthe esiology 200 01; 95(5): 11175–1181. PMID P 116844987

D Developm ments of La aryngeall Mask Aiirway In n 2002 a va ariation off the classiccal LMA was w introduced. It incoorporates an a oeesophageall (posterior) cuff and d lumen forr venting of o stomach contents. It m maintains a seal with higher h airw way pressu ures than th he standarrd LMA. Acccurate fixxation is reequired in order to m maintain th he distal en nd at the up pper oesop phageal sp phincter.

Co ook TM, Lee G, Nolan JP. The Pro oSeal Laryn ngeal mask airway: a a rev eview of the 005; 52(7): 739–760. 7 PMID P 161033390 literatture. Can J Anaesth 20

A single-usee LMA-type e supraglo ottic airway y, e.g. i-gel,, has a gel--filled non-in nflatable seeal. It moullds to the p pharyngeall, laryngea al and perillaryngeal sttructures and a claims to reduce p pressure on airway mucosal m sur urfaces. Wh hen co orrectly insserted, the tip of the ii-gel is loca ated at the e entrance tto oesopha agus an nd the ‘gasstric chann nel’ allows ffor suction ning of the oesophagu us and stom mach, paassing of a nasogastrric tube and d venting of o trapped gas. It is cllaimed tha at op ptimum po ositioning is i more oftten achieveed with the e i-gel. In ntubating g larynge eal mask k airway Itt is possiblee to pass a size 6.0 m mm trachea al tube thou ugh a stand dard LMA into th he trachea. However this is not always succcessful an nd the LMA A must be left l in siitu. A modiification off the LMA h has been developed d specifically s y to aid in ntubation. The T Intuba ating LMA A (iLMA) ha as a steel tube which h is shorter and of w wider bore than t the sillicone tubee of the sta andard LM MA. There iss a bar at the diistal opening that allo ows the ep piglottis to be lifted an nteriorly. T Through th his will paass a special size 8 ET TT with a ssoft tip and d a narrow w cuff. The p process of using th he iLMA to o place an ETT E is show wn the figu ures below w.

[25]

Task 2. Aiirway interven ntions

© Janet Fong 2010. Repro oduced from www.aic.cuh hk.edu.hk/web8 htttp://www.aiic.cuhk.edu.h hk/web8/iLM MA.htm

O Oesopha ageal-tra acheal d ouble lu umen de evice A As the namee suggests this is a do ouble lumeen tube witth luminaee that end at a ap pproximately the sam me level. Th he oesopha ageal lume en has eigh ht perforatiions th hat are inteended to be e located aat the level of the lowe er pharynxx. This lum men is bllind at the distal end. The otherr lumen (trracheal) is open at th he distal en nd and un nperforateed througho out. Theree are two ba alloons, on ne smaller d distal and a laarger proximal balloo on. The largger balloon n fixes the combitubee in the hyypopharyn nx. The disttal balloon n forms a seeal either in i the oesoophagus or the trrachea. Ma arketed as Combitube C e™, the dev vice can be e inserted bblindly or with w th he aid of a laryngosco l ope. In n about 95% % of the ca ases the com mbitube en nds up inserted into the oesoph hagus. V Ventilation then takess place via tthe perfora ations in th he wall of tthe oesoph hageal tu ube. It is in ndicated on nly in the ‘ccannot intu ubation–ca annot venttilate’ situa ation. Itts major disadvantage is that no o tracheal suctioning s is possiblee if the disttal lu umen is pla aced in the oesophagu us (the mo ost likely po osition).

C Cricothyr roidotom my Crricothryoid dotomy ma ay be perfo ormed as a percutane eous or opeen surgicall prrocedure.  

p ous insertio on of a can nnula throu ugh the criccothyroid The percutaneo mem mbrane into o the airway ay will allow w apnoeic (low ( pressu ure) or jet (high presssure) ventillation to b e performeed. Surgiically open ning the meembrane will w allow th he passagee of a smalll trach heostomy tu ube througgh which ventilation v can take p place.

Th he indicatiion for both h these tecchniques iss in the ‘can nnot intubbate–canno ot veentilate’ sittuations wh hich are raare. While puncturing g the trach hea is a siignificantlyy invasive procedure, p , it should be perform med beforee critical hy ypoxia haas occurred d. Crricothyroid dotomy is usually u resserved for emergency e y airway acccess, howe ever, th he techniqu ue is simila ar to inserttion of a minitracheo m stomy.

Pra actise the te echnique in the simulattion situatio on or as parrt of anotherr prrocedure e.g g. transtrach heal injectio on or inserttion of a ‘miinitracheosttomy’ tube. Avoid th he first timee being the ‘ffailure to in ntubate–faillure to ventilate’ scenar ario.

[26]

Task 2. Airway interventions

Equipment       

Cannula with or without catheter Non-kinking dilator Guide wire Syringe Lignocaine (lidocaine) Scalpel Minitracheostomy tube.

Seldinger technique      

    

100% oxygen by face-mask or bag-mask ventilation by assistant. Extend the neck if possible. Prepare the skin with antiseptic. Palpate the landmarks of the thyroid and cricoid cartilages in the midline. The cricothyroid membrane is a trapezoid shaped membrane lying between these two cartilages. Anaesthetise the skin with subdermal lidocaine and adrenaline. Insert a needle and cannula through the skin and cricothyroid membrane perpendicularly while aspirating until air enters the syringe. Make sure that the opening of the sharp end is directed caudal. Do not advance further and do not enter the oesophagus. Remove the needle while slightly advancing the cannula. Insert guide wire. Often this will provoke coughing. The wire should advance without resistance. Do not force it. Perform a small incision in the skin at the entry point of the guide wire. A dilator is inserted over the guide wire and then removed. A mounted minitracheostomy tube may be threaded into the trachea. Remove the inner dilator. Pass a suction catheter into the trachea to confirm that there is no obstruction.

Ventilation through the cricothyroidotomy There are several techniques for ventilating through the cricothyroidotomy some of which require preparation. It is imperative that the equipment should be preassembled on the difficult airway trolley or bag. There is unlikely to be the time during an emergency, ‘failure to intubate–failure to ventilate’ scenario. There are new commercial preassembled devices available. Complications of cricothyroidotomy Although the technique may be complicated by bleeding, airway compromise or tube misplacement, complications are usually due to ventilation and include:  Barotrauma  Aspiration  Inadequate ventilation. [27]

Task 2. Airway interventions

Tracheostomy Tracheostomy, performed either as an open (surgical) or percutaneous technique, is a long-term alternative to orotracheal or nasotracheal intubation. The latter technique is now more common and uses a Seldinger technique to place a guide wire in the trachea. The track to the trachea is then dilated using single or multiple dilators (or more recently by inflating a balloon) passed over the wire (see below). The procedure is performed under bronchoscopic control. Percutaneous tracheostomy is usually performed in the ICU by the intensivist whilst almost all operative tracheostomies are performed in the operating theatre/room. The advantages of a tracheostomy are:   

Patient comfort and reduced need for sedation Reduction in supra-and subglottic trauma/scarring Patient has potential to speak.

The indications are:       

Failure to wean from mechanical ventilation Prevention of damage to vocal cords and subglottic region Absence of protective airway reflexes Inability to maintain a patent airway Need for tracheobronchial toilet with suctioning As part of a surgical procedure e.g. laryngectomy Prolonged or anticipated prolonged invasive ventilation.

Contraindications (both techniques):  

Arterial injury in neck Coagulopathy (depending on the type of procedure).

Contraindications (percutaneous technique):  

Abnormal anatomy Suspected cervical spine instability.

Complications:  Unsuccessful placement (failure)  Incorrect placement (apparent success)  Haemorrhage  Local infection; might particularly compromise patients who have required surgical fixation following cervical spine injury. Earlier studies comparing percutaneous and surgical tracheostomy suggested more minor complications with percutaneous tracheostomies. However, the message from a significant number of studies and meta-analyses is that the percutaneous technique has similar operative complications, fewer infective complications, shorter scars with better cosmetic results and possibly less [28]

Task 2. Aiirway interven ntions

blleeding. Since it is pe erformed aat the bedsiide, it is su uperior in tterms of co ost and prracticality

Gyysin C, Dulg guerov P, Guyot G JP, Peerneger TV, Abajo B, Ch hevrolet JC C. Percu utaneous verrsus surgicaal tracheosttomy: a double-blind raandomized trial. Ann A Surg 19 999; 230(5)): 708–714. PMID 1056 61096 Raaghuraman n G, Rajan S, S Marzouk JJK, Mullhi D, D Smith FG G. Is tracheeal stenosis causeed by percuttaneous traccheostomy different d fro om that by ssurgical tracheeostomy? Chest C 2005; 127(3): 879 9–885. PMIID 157647711 H Higgins KM, Punthakee X. Meta-an nalysis comparison of open o versuss –454. PMID percu utaneous tra acheostomyy. Laryngosccope 2007; 117(3): 447– D 17334 4304 Delaney A, Bagshaw SM M, Nalos M. Percutaneo ous dilatatio onal tracheoostomy verssus surgiccal tracheosstomy in criitically ill pa atients: a sy ystematic reeview and meta--analysis. Crit Care 200 06; 10(2): R55. R PMID 16606435 1

T Timing off tracheos stomy: ea arly versu us late At what poin nt in the ca are of a pattient who is i ‘failing to o wean’ sh hould a trracheostom my be perfo ormed? Th here is no co oncensus on o this poin nt – as earrly as seeven days or o as late as a 21 days aare not unccommon. However, H in n a patientt who deefinitely reequires the e proceduree (e.g. for airway a prottection) it seems sensible to peerform it early e to pro ovide the ad dvantages of comfortt and reducced sedatio on. The reeferences below b discu uss the facttors which h influence the timingg of tracheo ostomy.

Griffiths J, Barber VS, Morgan M L, Y Young JD. Sy ystematic re eview and m meta-analyssis of stu udies of the timing t of trracheostomy y in adult patients und dergoing artificcial ventilation. BMJ 20 005; 330(7502): 1243. PMID 1590 01643 Durbin CG Jrr. Tracheosttomy: why, when, and how? Respir Care 2010 0; 55(8): 1056– –1068. PMIID 2066715 3 Teerragni PP, Antonelli M, M Fumagallli R, Faggia ano C, Berarrdino M, Paallavicini FB B, et al. Early E vs late e tracheoto my for prev vention of pneumonia p iin mechanically ven ntilated adu ult ICU patieents: a rand domized con ntrolled tria al. JAMA A 2010; 303 3(15): 1483– –1489. PMIID 2040705 57 Trrouillet JL, Luyt CE, Gu uiguet M, O Ouattara A, Vaissier E, Makri R, ett al. Early percu utaneous tra acheotomy vversus prolo onged intub bation of meechanically ventillated patien nts after card diac surgery y: a random mized trial. A Ann Intern Med 2011; 2 154(6): 373–383 . PMID 214 403073

P Percutane eous trach heostomy y    

Posittion the pattient with a roll beneeath the shoulders to extend the e neck. Prepa are the necck as abovee. Palpa ate the criccoid and th he upper trracheal ring gs and infil iltrate with h ligno ocaine (lido ocaine) and d adrenalin ne if necesssary. Adva ance fibre optic o scopee through the t trachea al tube. [29]

Task 2. Aiirway interven ntions

       

With hdraw the tracheal tub be until the cuff lies at a or below w the cordss and can be b kept infllated to maaintain a seeal for venttilation. When n using the e Ciaglia orr Griggs technique make m a 1.5– –2 cm transsverse incisiion over th he second ttracheal rin ng and blunt dissect tto the trach hea. Undeer fibre opttic vision p puncture th he trachea in the mid dline until air a is aspirrated. Inserrt a J tipped Seldingeer wire again checking that this is in the midline. m The dilating d tecchniques u use sequenttial dilators (Ciaglia ttechnique)), a forceeps (Griggss techniquee), a single rhino dilator or a scrrew (Percu utwist). Oncee dilated re emove the d dilators an nd then insert a trach heostomy tu ube. Inflatte the cuff.. Place a su uction cath heter through the tub e to remov ve blood d and secre etions and confirm tu ube positio on using th he endoscop pe. Obtain chest X--ray to con nfirm position and ru ule out com mplications. F tecchnique forr percutan neous trach heostomy in nvolves The Fantoni retrograde intu ubation of tthe trachea a using a sp pecially-deesigned tra acheal m comp plex technique and is not as wid dely practissed. Its tube.. This is a more propo onents claiim that it ccan be used d safely in patients w with bleedin ng tendeencies beca ause of thee tension on n the tissues.

Q Q. What ar re the com mplicatio ons of per rcutaneou us trache eostomy and a w which are the mostt common n? A.. A large nu umber of com mplicationss have been reported with w percutan aneous trracheostomyy including death, bleeeding, pneum mothorax, subcutaneou s ema, us emphyse tu ube displaceement, stom mal infection n, pneumon nia, tracheall stenosis, trracheooeesophageal fistula.

Paappas S, Ma aragoudakiss P, Vlastaraakos P, Assiimakopoulo os D, Mandrrali T, Kandiiloros D, et al. Surgicall versus perrcutaneous tracheostom t my: an eviden nce-based approach. a E Eur Arch Oto orhinolaryn ngol 2011; 2268(3): 323– – 330. PMID P 2095 57486 Baarbetti JK, Nichol N AD, Choate KR R, Bailey MJ, Lee GA, Cooper DJ. P Prospective observvational stu udy of posto operative co omplications after perccutaneous Crit Care dilata ational or su urgical trach heostomy in n critically illl patients. C Resussc 2009; 11((4): 244–24 49. PMID 20 0001871 M Mallick A, Bo odenham AR R. Tracheosstomy in criitically ill pa atients. Eurr J Anaessthesiol 20110; 27(8): 6 76–682. PM MID 205232 214

[30]

Task 2. Aiirway interven ntions

Observe five percutaneou p us tracheosttomies and five f operativ ive tracheosstomies to o compare and a contrastt the differeent techniqu ues.

In the t Intensiv ve Care Uniit or by visitting the Ana aesthetic Reecovery Ward, ob bserve the various v meth hods of oxyygenation/a airway mana agement bei eing used on n paatients e.g. simple s oxyg gen mask, o oropharyngeeal airway, endotrache e eal or trache eostomy tu ube. Consideer why diffe erent techniiques are ussed in differrent patientts.

T Tracheosttomy tube es M Modern traccheostomy y tubes are made of plastic p and may be claassified by various asspects of th heir constrruction. Tu ubes may be cuffed orr uncuffed,, single or double d lu umen (with h an inner removable r e cannula), fenestrate ed or non-ffenestrated d and m may have an n adjustablle (rather tthan fixed)) flange. In n addition, they may have h fo oamed filleed cuffs, or have speciific shapess or dimenssions for p particular clinical c siituations. The T inner removable r cannula iss an importtant safetyy feature in n the evvent of traccheal obstrruction, seee Task 5.

H Hess DR. Tra acheostomy y tubes and related app pliances. Respir Care 20 005; 50(4): 497–5 510. PMID 15807912

[31]

Task 3. Re ecognition of eeffective ventilation

3. RE ECOGN NITION OF O EFFECTIVE E VENTIILATION N Th he critical care physician shoulld be awaree that one of o the majoor causes of o death orr severe brrain damag ge in anaessthesia rela ates to the failure f of vventilation due to th he misplaceement of th he endotraacheal tubee. Unrecognised oesoophageal in ntubation is as likely to t occur in n the situattion of apparently un ncomplicate ed in ntubation as a in the diifficult intu ubation sceenario. The e outcome may be mo ore deevastating in the unccomplicated d intubatio on because e of the pottential dela ay in th he appeara ance of clin nical signs aand the relluctance to o believe th hat the en ndotrachea al tube hass been misp placed. A fit 20-year-olld man wass anaesthetised for an n emergen ncy aappendecto omy. He wa as pre-oxyggenated fo or five minu utes. A rap pid sequencce in nduction and a endotra acheal intu ubation wa as performed and air entry was heard b bilaterally. Ten minuttes into thee procedurre the patie ent’s oxygeen saturatio on fell. T The patientt suffered a cardiac arrrest. A mo ore experie enced assisstant arrive ed and cconnected an a end-tida al carbon d dioxide mo onitor. End d-tidal carbbon dioxide was aabsent. Thee tracheal tube t was reemoved fro om the oesophagus aand reposittioned in th he trachea. The patie ent was ressuscitated but b suffere ed severe h hypoxic bra ain in njury resullting in a persistent p vvegetative state. s P Pre-oxygen nation allow wed the oessophageal intubation n to go unrrecognised for ten m minutes by which stag ge the intu ubator was reluctant to t believe tthat the tub be was m malposition ned.

C Correct tracheal t l tube po ositionin ng Th he optimall position for f the traccheal tube ensures th hat the upp per end of the t cuff liees 1–3 cm below the vocal cord ds and the tip t of the tu ube lies 2– –3 cm abov ve the caarina. A Anatomy o of the air rways In n the adult, the distan nce from th he incisorss to the voccal cords iss 12–15 cm m. The leength of thee trachea from f the un nderside off the vocal cords to th he carina is ap pproximately 11 cm. The T distan nces may diiffer depen nding on geender and an natomy bu ut in genera al the distaance from the t distal end e of the ttracheal tu ube to th he incisors will be 21 cm in wom men and 23 3 cm in me en.

Flex xion and ex xtension of tthe cervical spine can result r in moovement of the t trracheal tubee up to 3.5 cm c and conssequently ca an result in accidental misplaceme ent of th he tube. This is a particcular risk in children.

C Confirma ation off trachea al tube placeme p ent

Onlly two meth hods are saffe to prove correct c endo otracheal tu ube position n: direct viisualisation of the trach heal tube beetween the vocal v cords and positivve measurem ment of en nd-tidal carb bon dioxide e.

[32]

Task 3. Re ecognition of eeffective ventilation

V Visualisin ng the tub be passing g into the e trachea a his should be the gold standard d in assessiing the corrrect Th po ositioning of the traccheal tube. It is of no benefit if a good view w off the larynx x cannot be achieved d. Howeverr, operator error can occcur and th he intubato or is often reluctant to t believe that t oeesophageall intubatio on has occu urred. Thiss may lead to a deevastating delay in making m the diagnosis (see above e anecdote)). In n addition, accidental dislocatio on of tube may occurr when reemoving th he laryngosscope.

Clinical tests: LOOK K, LISTEN and a FEEL

C Chest walll moveme ent on ma anual ven ntilation Itt is often po ossible to see s chest m movementss on manua al ventilatiion; howev ver ch hest wall movements m s may be diifficult to see s in the obese o or in the presen nce of aiirway obstrruction. Fo ollowing (in nadvertentt) intubatio on of the ooesophaguss, m manual venttilation willl cause infflation of the stomach h which m may give the e ap ppearance of chest wall w movem ment. P Presence of o water vapour v c condensin ng on the tracheall tube (‘‘misting’)) Cyyclic appea arance of ‘m misting’ on n the wall of o tracheal tube durin ng exhalatiion is a po ointer to su uccessful tracheal inttubation. However, H water w vapou ur is also prroduced from the oessophagus w which may y be misleading. The aabsence off water vaapour is ussually indiccative of oeesophageall intubation. A Auscultatiion of bre eath soun nds Bo oth axillaee should be e carefully aauscultated d for clear vesicular bbreath sou unds.

Bew ware. There e are usuallyy transmitteed sounds audible overr the anterio or chest w wall with oessophageal in ntubation esspecially in children. In n blunt thorracic traum ma or in ceertain pulmonary patho ologies (esp pecially unillateral), dim minished breeath soundss may no ot indicate a wrong tub be position.

C Complianc ce of the reservoir r r bag he charactteristic feelling of the rreservoir bag b during manual veentilation is i not Th allways relia able as gas coming baack from th he stomach h can have a similar fe eel. E End-tidal carbon dioxide d Besides direect visualissation of co orrect tubee placement, detection n of end-tiidal caarbon diox xide is the second s reliiable sign of o correct tracheal t tubbe placement. Q Q. What ar re the situ uations w where end d-tidal ca arbon diox oxide m monitorin ng may be e misleadiing? [33]

Task 3. Re ecognition of eeffective ventilation

A..  

After oesophagea al intubatio on, carbon dioxide d may y be detected d (from the stoma ach) if signiificant gastrric inflation n has occurred during m manual venttilation with a mask. Thiis should ce ase after 2– –3 ventilato ory cycles. After oesophagea al intubatio on, carbon dioxide d may y be detected d on capnog graphy wheree carbonate ed drinks haave been tak ken shortly prior to thee intubating g event. The end-tidal e lev vels of carbo on dioxide should s decrrease relativvely quickly.

End d-tidal carbon dioxide should be monitored m for f at least ssix respirato ory cyycles before being taken n as a confirrmatory tesst.

En nd-tidal ca arbon dioxide monito oring may not alwayss be availabble especia ally in th he emergen ncy situatio on. Dispos able devicees which work w on collourimetry y can be usseful in thee emergenccy situation n. N Negative pressure p devices N Negative preessure dev vices rely on n the princciple that iff negative p pressure iss ap pplied to a tube in the oesophaggus that occclusion wiill occur ass the oesop phagus co ollapses around the tube. A 50 m ml syringee with a cattheter tip aattached to o the tu ube via a ca atheter mo ount can bee used with h success.

Atteempt to con nstruct a neegative presssure device and get thee feel for the e no ormal in thee elective situation. Ch heck your em mergency airway equip pment for th he range off devices req quired. There will not b be the time in the emerrgency situaation. Such deetection devvices should d not be neccessary wheere ETCO2 monitoring m iis available.

Fi Fibre optic c confirm mation Al Although vissualising th he carina vvia a fibre optic o bronchoscope w will confirm m co orrect placement, this techniqu ue is often only o of pra actical beneefit where the sccope has beeen used to o perform tthe intuba ation. R Radiology y W Whilst a cheest X-ray will w be of litttle use in the t acute situation, s th the correct po osition of the t trachea al tube sho ould be con nfirmed in all patientss in intensive caare. Howevver, an app parently no ormal chestt X-ray app pearance d does not gu uarantee co orrect traccheal placem ment of a tube t (orotrracheal or ttracheosto omy). [34]

Task 3. Re ecognition of eeffective ventilation

Q Q. Where is i the opttimal possition of th he trache eal tube o on the che est Xra ay? Give three t pos ssible mal alposition ns. See the e images below.

al tube shou uld lie appro oximately 2– –3 cm abovve the carina a. The A.. The tip of the trachea tu ube may be misplaced into i the:    

Rightt main bronchus Left main m bronch hus At thee level of the vocal cord ds with cufff outside the e cords Outsiide the airw way.

[35]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

4. TH HE DIFF FICULT T AIRWA AY: ALG GORITH HMS & ADJU UNCTS TO T MAN NAGEM MENT Th he difficultt airway ha as been deffined as a clinical c situ uation in w which a con nventionally y trained aanaesthesio ologist exp periences diifficulty wiith mask ve entilation, tracheal in ntubation, or both. Itt iss a situation n in which the conven ntionally trained t crittical care ph hysician seeeks expertt anaesthessiology asssistance.

Prepa aration is th he key to success in i managing m th he diffiicult airway y. The mosst importan nt deteerminants of o success arre esta ablished lon ng beforre the patien nt is encountereed

Crritical incid dents relatted to airw way manageement may y have devaastating co onsequencces ranging g from hypo oxic brain injury to death. d The llikelihood of diisaster is greatly g dim minished if tthe difficullt intubatio on is anticiipated. Tho orough paatient asseessment will reduce th he inciden nce of unreccognised d difficult in ntubation. U Unfortunateely all difficult intubaations are not n predicttable. It is of paramo ount im mportance that those e involved iin any form m of airway y managem ment possess a raange of tech hniques to o deal with the unantiicipated diifficult airw way. Al All airway manoeuvre m s in the criitically ill patient p sho ould be anti ticipated ass diifficult. Even where the t grade o of laryngea al visualisattion is knoown to be easy, e th he patient may m be hyp poxaemic aand cardio ovascularly unstable. Re-intuba ations m may be com mplicated by y laryngeall oedema, upper airw way secretioons and ga astric co ontents.

D Difficult airway guidelin nes wo algorith hms are sh hown: Tw D Difficult airw way algoritthm 1 htttp://pact..esicm.org//courses/A AIRMAN/sscorm/airw way_manaagement/pd df/Air M Man_algoriitm1.pdf D Difficult airw way algoritthm 2 htttp://pact..esicm.org//courses/A AIRMAN/sscorm/airw way_manaagement/pd df/Air M Man_algoriitm2.pdf Fu urther info ormation iss given in tthe referen nces below..

Laavery GG, Jamison J CA. Airway maanagement in the criticcally ill adullt. In: Parrilllo, JE, Dellinger RP, ed ditors. Critiical Care Medicine: Priinciples of Diagn nosis and Management M t in the Adu ult. 3rd ed. Philadelphia P a: Mosby Elseviier; 2008. ISBN I 978-0 0-323-048411-5. pp. 17– –37

[36]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

Laavery GG, McCloskey M BV. B The diffficult airway y in adult crritical care. Crit Care Med 2008; 2 36(7)): 2163–21773. PMID 18 8552680 H Henderson JJ, J Popat MT T, Latto IP, Pearce AC.. Difficult Airway A Socieety guidelines for management of the unan nticipated difficult d intu ubation. Anaaesthesia 2004; 59(7): 675 5–694. PMI D 15200543 3 Prractice guid delines for managemen m nt of the diffficult airway y: an updateed report by y the Am merican Society of Aneesthesiologiists Task Fo orce on Man nagement off the Difficult Airw way. Anesth hesiology 20 003; 98(5): 1269–1277.. PMID 12717 7151 Jaanssens M, Hartstein G. G Managem ment of diffiicult intubattion. Eur J A Anaesthesio ol 2001;; 18(1): 3–12 2. PMID 112 270007 Crrosby ET, Cooper C RM, Douglas MJJ, Doyle DJ J, Hung OR R, Labrecquee P, et al. Th he unantticipated diffficult airwaay with reco ommendatio ons for man nagement. Can J Anaesth 19 998; 45(8): 757–776. Review. R PMIID 9793666 6 Beenumof JL. Laryngeal mask airwaay and the ASA A difficultt airway alggorithm. 9797 Anestthesiology 1996; 84(3):: 686–699. PMID 8659 Beenumof JL. Manageme ent of the diifficult adullt airway with special eemphasis on n awakee tracheal in ntubation. A Anesthesiollogy 1991; 75(6): 1087– –1110. PMID D 18245 555

p://www.a asahq.org/p publication nsAndServ vices/practticeparam.htm Liink to: http

Ma any nationall bodies/soccieties havee published difficult airrway guideliines. Go on nline and trry to find yo our own natiional guidance and com mpare it witth the guide elines w within this module. m

D Difficult intubation D Difficult intu ubation may be conssidered und der three headings: h   

Anticcipated diffficult intub bation Unan nticipated difficult d in ntubation Failu ure to intub bate and faailure to ventilate.

A Anticipate ed difficu ult intuba ation A 35--year-old m man requirred intubattion and geeneral anae esthetic fo or internall fixation of facial fracctures follo owing an assault a whiilst intoxica ated. An aawake fibree optic intu ubation wa s attempteed but the patient p wass uncooperrative aand combattive. When n sedation w was admin nistered, th he patient'ss breathing g b became laboured and d obstructed d. Further sedation was w admini nistered and d the p patient beca ame apnoe eic. Intubat ation was atttempted; however th he larynx was w not vvisible. A crricothryoid dotomy waas performeed to main ntain oxygeenation and da trracheostom my was req quired. W Whenever difficulty d with w intubattion is antiicipated there are sevveral decisiions reequired to determine e the best co ourse of acction.

[37]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

Sttep 1: Sho ould the patient p be e awake or o anaestthetised A Anticipated difficult in ntubationss, where thee difficulty y is viewed as significcant, sh hould be peerformed using u an aw wake techn nique wherrever possiible. For ‘le esser’ deegrees of difficulty, d anaesthesia a a and the use u of adjun ncts descriibed later in i this Taask may bee appropriate. This iss a significa ant ‘judgm ment call’ in nvolved, re equiring co onsiderable care and experiencce. Awa ake techniq ques may rrequire mo ore time, re equire addi ditional ope erator sk kills, especcially in pro oviding airrway anaessthesia and d may be m more unplea asant fo or the patieent. Th he benefitss of awake techniquees normally y outweigh the risks ssince:  

The risks r of hyp poxia are ggreatly dim minished ass the patien nt can be kept k sponttaneously breathing b throughou ut the proce edure. The awake a patient can maaintain thee tone of th he upper aiirways allowing separration of th he structurres from on ne another. This allow ws improve ed visua alisation off the larynxx.

Sttep 2: Wh hich awak ke techniique is mo ost appro opriate: F Fibre optiic or re etrograde e? bre optic endosco opy Fllexible fib   

Mostt popular and a accessib ible awake technique for intubaation. Requ uires specia alist equipm ment, train ning and practice and d is not suiitable for alll patients. When n used app propriatelyy, it is a rap pid safe tecchnique witth a high le evel of succeess.

Q Q. What ar re the con ntraindiccations to o awake fiibre opticc intubatiion? A..    

Unwilling patien nt despite ad dequate preeparation. Inexp perienced op perator – th his should not n be underrestimated as the poten ntial for airwa ay disaster iss greatly inccreased. Bleed ding may ob bscure the viiew. Subgllottic obstru uction – wh here the tube may not pass p into thee trachea.

R Retrograd de techniq ques   

Used d for severa al decades aand recenttly have become morre popular becau use of the developme d ent of new equipmentt and the ccombinatio on of retrograde and fibre opticc techniquees. Retro ograde tech hniques haave been sh hown to be e of particu ular benefitt in maxillofacial trauma. As wiith the other awake ttechniques, considera able skill an nd practice e are necesssary to en nsure a high h degree off success. [38]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

Sttep 3: If general g an naesthesiia is used d, which technique t e is s most appropriate e

Make th he first attempt at a any inttubation thee most efffective. Op ptimise thee patient po osition and have all the neceessary equip pment imm mediately to o hand

Th here will be b some cirrcumstancees where an n awake te echnique m may not be feasible f (w when dealin ng with thee uncooperrative paatient) or necessary n (if ( the degrree of difficculty is nott thought tto bee severe). If I general anaesthesia a a is to be in nduced the en the uttmost caree should be e taken with h preparattion of the patient, asssistance and a equipm ment.    

Ensu uring an em mpty stomaach – use a large naso ogastric tub ube if requiired Optim mal positio oning Prolo onged pre-oxygenatio on with fulll monitoring applied d Prepa are all the necessary adjuncts to difficult intubation i n (see below w) o Gum ela astic bougiee dles o Range off laryngosccope blades and hand o Introduccers o Video larryngoscopyy equipmeent o Illumina ating styletts al mask airrways o Laryngea acheal kit. o Transtra

Th he patient should be kept sponttaneously breathing at all timess until the op perator is sure s that both b intubaation and ventilation v are possibble. If laaryngoscop py is perforrmed and iintubation is found to o be difficu ult, repeate ed atttempts at intubation n should bee avoided as a the likeliihood of siignificant adverse a efffects increeases with prolonged p attempts and a increa ased use off force.

Do not admin nister a mu uscle relaxa ant (neuromuscular bblocking drug) if th here is conccern aboutt the abilityy to visualiise and intu ubate the llarynx. U Unanticip pated diffi ficult intu ubation Evven with proper p patient assessm ment and selection, s not n all diifficult intu ubations arre predictaable. The fo ocus must be to m maintain ad dequate oxy ygenation at all times. If at any y stage, veentilation by b mask be ecomes diffficult, the procedure should bee ab bandoned, the patien nt awakeneed (if feasib ble) and th he airway sh hould be seecured und der local an naesthesia if possible e. Skilled asssistance sh hould be im mmediatelly sought.

Preveention is bettter than curre. Avoid reach hing this situation by wakeening the patieent when diff fficulty is enco ountered

Laavery GG, McCloskey M BV. B The diffficult airway y in adult crritical care. Crit Care Med 2008; 2 36(7)): 2163–21773. PMID 18 8552680 Bo okhari A, Benham SW,, Popat MT.. Managemeent of unanticipated diifficult intuba ation: a surrvey of curreent practicee in the Oxfo ord region. Eur J Anaessthesiol 200 04; 21(2): 12 23–127. PM MID 1497734 43

[39]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

Laavery GG, Jamison J CA. Airway maanagement in the criticcally ill adullt. In: Parrilllo, JE, Dellinger RP, ed ditors. Critiical Care Medicine: Priinciples of Diagn nosis and Management M t in the Adu ult. 3rd ed. Philadelphia P a: Mosby Elseviier; 2008. ISBN I 978-0 0-323-048411-5. pp. 17– –37

Siimple tec chniques for the un unanticipa ated diffic cult intub bation U Use the simple techniq ques below w frequentlly. Optimissing every iintubation n will siignificantlyy reduce yo our inciden nce of difficculty and improve yoour techniq que w with these devices. d B BURP and d Bimanual Laryng goscopy Backward Upward U and d Right Preessure (BU URP) over the t larynx often imprroves th he view at laryngosco l opy. Howevver, when performed p by an assiistant who cannot seee its effectt on the larryngeal possition, it ha as been shown to wo rsen view in i over 30 0% of casees. The optiimal degreee and direction of prressure on tthe larynx can be fo ound by thee intubatorr using triaal and erro or and, whe en the optim mum view w has beeen achievved, mainta ained by an n assistant. This is kn nown as Bim manual Laaryngoscop py or Exterrnal Laryn ngeal Manip pulation (E ELM).

Leevitan RM, Kinkle WC,, Levin WJ, Everett WW W. Laryngeal view duriing laryng goscopy: a randomized r d trial comp paring cricoiid pressure,, backward-upward-rightwarrd pressure,, and biman nual laryngo oscopy. Ann n Emerg Me ed 2006; 47(6): 548 8–555. Epub b 2006 Marr 14. PMID 16713784 Yeentis SM. Th he effects of single-han nded and biimanual criccoid pressu ure on the view at a laryngosccopy. Anaessthesia 1997 7; 52(4): 332–335. PMIID 9135184 4 Sn nider DD, Clarke C D, Fin nucane BT. The ‘BURP P’ maneuverr worsens th he glottic view when w applie ed in combiination with h cricoid pre essure. Can n J Anaesth 2005;; 52(1): 100–104. PMID D 15625265 5

Presssure is exerted on th he thyroid cartilage not n to the ccricoid! U Use of a Gu um Elastic Bougie e Th he gum ela astic bougie is a long,, blunt-end ded, semiriigid introd ducer which h is ad dvanced (ssometimes blindly) th hrough a poorly visua alised (or u unseen) larrynx an nd into thee trachea. Its I insertio on into the trachea may be confi firmed by feeling fe (N NOT hearin ng) the ‘clicks’ as the bougie run ns over the e tracheal rrings. The patient m may cough (if ( muscle relaxation r is not com mplete). A tracheal t tub ube can then be raailroaded over o the bo ougie. The ttip of the tube bevel may m catch on the righ ht vocal co ord. If so th he tracheall tube shou uld be rota ated anticlo ockwise thrrough 90° and ad dvanced. M Many view the t gum elastic bougiie as the beest single adjunct a in aairway m managemen nt. Howeve er it may bee of limited d value wh hen it is nott possible to t ellevate or viisualise the e epiglottiss. There ha ave also bee en reports suggesting g an in ncreased frrequency off failure wiith the more recently y introduceed single-u use [40]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

bo ougie. It must m be use ed with caree as vigoro ous advanccement mayy perforate e the oeesophagus or even th he major aiirways.

H Hames KC, Pandit P JJ, Marfin M AG, P Popat MT, Yentis Y SM. Use U of the bbougie in simullated difficu ult intubatio on. 1. Comparison of th he single-usee bougie with the fib brescope. Anaesthesia A 2003; 58(9 9): 846–8511. PMID 129 911355 M Marfin AG, Pandit P JJ, Hames H KC, P Popat MT, Yentis Y SM. Use U of the bbougie in simullated difficu ult intubatio on. 2. Comp parison of single-use boougie with multip ple-use bou ugie. Anaestthesia 2003 3; 58(9): 852 2–855. PMIID 12911356 6 Laatto IP, Staccey M, Meck klenburgh JJ, Vaughan RS. Survey y of the use oof the gum elasticc bougie in clinical praactice. Anaesthesia 200 02; 57(4): 3779–384. PMID D 11939998

U Use of a Sttylet (Intr roducer) or Lighte ed Stylet/ /Light Wa and he stylet iss a smooth,, malleablee metal or plastic p rod d that is plaaced inside ea Th trracheal tub be (ETT) to o adjust thee curvaturee, typically y into a J orr ‘hockey-sstick’ sh hape to allo ow the tip of the ETT T to be direected throu ugh a poorlly visualise ed or un nseen glotttis. The sty ylet should d not projecct beyond the t end of the ETT to o avoid po otential airrway injury y. Th he lighted stylet (ligh ht wand) iss a malleab ble fibre op ptic light soource on wh hich an ET TT can be mounted and a subseq quently railroaded into the tracchea when the ligght source has passed d beyond tthe glottis. By trans-illuminatioon of the so oft tisssues of th he anterior neck it disstinguishess the trache eal lumen ffrom the (more po osterior) oesophaguss. Low amb bient lightiing is requiired for its use. The use u of th he lighted stylet s may facilitate b blind intub bation with h a reduced d stress response an nd reduced d neck mov vement. Ho owever, intubation using u the ligghted style et may taake longer than some e other tech hniques/prrocedures and it is un nsuitable for f the ob bese patien nt with a th hick neck.

Jaain S, Bhada ani U. Lighttwand: a usseful aid in faciomaxilla f ary trauma.. J Anesth 2011; 25(2): 291– –293. Epub b 2011 Jan 20. 2 PMID 211249400 In noue Y, Kog ga K, Shigem matsu A. A ccomparison n of two traccheal intubaation techn niques with Trachlight T aand Fastracch in patients with cervvical spine disord ders. Anesth h Analg 200 02; 94(3): 667–671. 6 Ta able of conteents. PMID 11867 7394 Beenumof JL. Compariso on of the gu m elastic bo ougie and th he stylet. An naesthesia 1997; 52(4): 385–386. PMID D 9135199 H Hung OR, Steewart RD: Lightwand L iintubation: I–a new lig ghtwand devvice. Can J Anaessth 1995; 42 2(9): 820–8 825. PMID 7497567 7

U Use of a modified m la aryngosccope blade e  

Straig ght blade (1 ( of 2 stan ndard bladees used in US) McCo oy laryngoscope [41]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

 

Polio o blade Video o laryngosccope.

Yo ou will find d exampless of laryng oscopes in n the follow wing.

htttp://www.ffrca.co.uk [Resources//Physics and d Equipmen nt/Laryngosscopes] htttp://www.p penlon.com m/products//laryngosco opes/mc_co oy.html Seethuraman D, Darshan ne S, Guha A A, Charters P. A random mised, crosssover study y of thee Dorges, McCoy and M Macintosh la aryngoscope e blades in a simulated d difficu ult intubatio on scenario o. Anaesthessia 2006; 611(5): 482–4487. PMID 16674 4625 Co ook TM, Tu uckey JP. A comparison n between th he Macintosh and the M McCoy laryng goscope bla ades. Anaestthesia 1996; 51(10): 97 77–980. PM MID 898487 78 Ch hisholm DG G, Calder I. Experiencee with the McCoy M laryng goscope in d difficult laryng goscopy. An naesthesia 11997; 52(9):: 906–908. PMID 9349 9078

Con nsider using g a differen nt blade in so ome intuba ations with tthe approprriate in nvolvement of an experrienced userr of the blad de. If you ha ave access too a simulatiion suite peerform ten elective e lary yngoscopiess using two different laryngoscopee blades. Co ompare an nd contrast the individual blades ffor ease of use, u view at laryngoscop opy and pote ential un nwelcome effects. e

A Advanced techniqu ues for the e unantic cipated diifficult in ntubation n Iff intubation n cannot be accompliished with h simple tecchniques, tthe patientt should bee awakened if possiblle. Advancced techniq ques may be b used as aaids to intu ubation orr as rescuee technique es to mainttain oxygen nation whilst the patiient is bein ng aw wakened.

Succcess with any of the fo ollowing tech hniques relies more on n the skill off the op perator than n on the too ols themselvves. It is imp perative tha at experiencce is gained d in the usse of a widee range of ad dvanced airw way techniq ques.

U Use of the laryngea al mask aiirway or intubatin ng LMA Th he LMA ca an be used to achievee control off the airway y whilst a d definitive prrocedure iss performe ed or the paatient is aw wakened. It may be p possible to in ntubate blin ndly throu ugh an LMA A. This is technically difficult an nd is made e easier byy the use of o an intuba ating laryn ngeal mask k airway (se ee Task 2).

[42]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

Gerstein NS, Braude DA A, Hung O, S Sanders JC,, Murphy MF. M The Fasttrach Intub bating Laryn ngeal Mask A Airway: an overview an nd update. Can J Anaessth 2010; 57 7(6): 588–6 601. Epub 2010 2 Jan 29. PMID 201112078 R WH, W Johanssen MJ, Osb born I, Ovasssapian A. U Use of the Feerson DZ, Rosenblatt intuba ating LMA--Fastrach in n 254 patien nts with diffficult-to-maanage airwa ays. Anesthe esiology 200 01; 95(5): 11175–1181. PMID P 116844987

Q Q. What ar re the con ntraindiccations fo or insertio on of the laryngea al m mask airw way in the e emergen ncy settin ng? A.. Upper and d lower airw way haemorrrhage, full stomach, s vo omitus in ph harynx (posssibility off gastric asp piration), direct laryngeeal trauma, severe head d trauma (rrelative co ontraindicattion).

V Video lary yngoscopy y Th hese devices use digiital video teechnology and modiffied larynggoscope bla ades to im mprove visu ualisation of the glotttis. These have a monitor/displ play which allows viisualisation n of the tra acheal tubee as it moves through h the larynggeal openin ng and in ncreases th he operatorrs breadth of view fro om 15 degrees to 60 d degrees. Cu urrent exa amples incllude the GllideScope®, the McGrath® seriees 3 laaryngoscop pe, and the Storz C-M MAC® whicch have currved (Macin ntosh-like) ® bllades. The Pentax AW WS and A AirTraq® ha ave a straig ght (Millerr-like) blad de w which, like the t origina al, passes u under the epiglottis e and elevatess it by dire ect up pward presssure. They y also havee a channel to guide the t tracheaal tube. Al All these devvices prom mise usefuln ness in pattients with limited m mouth open ning and reeduced necck extensio on. Video laaryngoscop pic devicess might be used in a planned p w way in mana aging patie ents with d difficult airrways or ass (unplanneed) rescue deevices follo owing faile ed attemptss at intuba ation. In on ne study off 200 conse ecutive in ntubations,, see refere ence below w, the GlideeScope provided a larryngoscopiic view eq qual to or better b than n that of dirrect laryng goscopy. Su urprisinglyy, subseque ent trracheal intu ubation using the GliideScope was w slower requiring on average e an ad dditional 16 s comparred to thatt with stand dard directt laryngosccopy. Simillar fin ndings havve been desscribed by others. W While their popularity y is increassing, routin ne use is stiill an uncoommon occcurrence in i many he ealth systeems. As witth all such devices, faamiliarity with w the eq quipment facilitates f successful s use in the emergency y situation n. A recent metaan nalysis con ncluded ‘cu urrently avaailable datta do not prrovide stroong eviden nce that th hese devicees should supersede sstandard direct d laryn ngoscopy foor routine or o diifficult intu ubation’. This T view m may changee in the futu ure as our experience e in ncreases an nd these de evices undeergo techn nological re efinement.

[43]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

Saavoldelli GL L, Schiffer E, E Abegg C, B Baeriswyl V, V Clergue F, F Waeber JL L. Comp parison of th he Glidescop pe, the McG Grath, the Airtraq A and tthe Macin ntosh laryng goscopes in n simulated difficult airrways. Anaeesthesia 2008; 63(12): 1358–1364. P PMID 19032 2306 Osborn IP, Behringer B EC C, Kramer D DC. Difficullt airway ma anagement ffollowing supra atentorial crraniotomy: a useful ma aneuver with h a new devvice. Anesth h Analg g 2007; 105((2): 552–5553. PMID 17 7646543 F RA. A An evaluatio on of the GllideScope, a new video o Beenjamin FJ, Boon D, French laryng goscope for difficult airrways: a ma anikin study y. Eur J Anaaesthesiol 2006; 23(6): 517 7–521. PMID D 16672094 4 Co ook T, Woo odall N, Frerrk C, editorss. Major com mplicationss of airway m managemen nt in thee United Kin ngdom. 4th National Audit A Projectt of The Royyal College of Anaessthetists and The Difficcult Airway Society. Ma arch 2011. IISBN 978-190093 36-03-3. htttp://www.rrcoa.ac.uk/d docs/NAP4 4_Section1.p pdf Th hong SY, Liim Y. Video and optic laaryngoscop py assisted tracheal intu ubation–the e new era. e Anaesth h Intensive C Care 2009; 37(2): 219– –233. PMID D 19400485 5 Su un DA, Warrriner CB, Parsons P DG,, Klein R, Umedaly U HS, Moult M. T The GlideS Scope Video o Laryngosccope: rando omized cliniical trial in 2200 patientts. Br J Anaesth A 200 05; 94(3): 3 381–384. Ep pub 2004 Nov N 26. PMIID 15567809 Laai HY, Chen n IH, Chen A, A Hwang F FY, Lee Y. Th he use of th he GlideScop pe for tracheeal intubation in patien nts with ank kylosing spo ondylitis. Brr J Anaesth h 2006; 97(3): 419 9–422. Epub b 2006 Jul 7. PMID 16829671 Seerocki G, Beein B, Schollz J, Dörgess V. Manageement of the e predicted difficult airwa ay: a comparrison of con nventional blade b laryng goscopy with th videoassistted blade larryngoscopyy and the GliideScope. Eur E J Anaestthesiol 2010 0; 27(1):: 24–30. PM MID 198093 328 M Mihai R, Blaiir E, Kay H,, Cook TM. A quantitattive review and a meta-an nalysis of perforrmance of non-standar n rd laryngoscopes and rigid r fibreop ptic intuba ation aids. Anaesthesia A a 2008; 63((7): 745–760. PMID 18 8582261

Fllexible fib bre optic intubatio on Th he fibre op ptic scope is i undoubttedly of greeat benefit to those skkilled in itss use. It m may be of va alue in an unanticipa u ated difficu ult airway if it is ‘read dy to go’ an nd the exxpertise is immediate ely availablle. Bewaree the scenarrio in whicch the patie ent is allready in aiirway difficulty, timee is requireed to set up p the scopee and/or th he op perator has limited sk kill. F Failure to intubate e and failu lure to ve entilate

Thiis is an abso olute medicaal emergenccy, a life-thrreatening siituation, the reesponse to which w requires regular practice.

[44]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

Im mmediate e manage ement        

Give 100% oxyg gen Call for f help Oral and or nassal airway Attem mpt two pe erson mask k ventilatio on Attem mpt one further intub bation und der optimall condition ns–BURP, gum elastiic bougie and a best larryngoscopee IF FA AIL, attemp pt to insertt a laryngeeal mask airway or oeesophagealltrach heal double e lumen deevice IF FA AIL, procee ed rapidly tto invasivee airway su uch as need dle cricothyroidoto omy, minitrracheostom my by Seld dinger tech hnique or open cricothyroidoto omy ke state witth spontaneous ventilation, or cconsider Returrn to awak conveersion to trracheostom my ,or (if prospects p fo or successfful laryngo oscopy can be b improve ed), oral orr nasal intu ubation.

Th here are feew indicatio ons to perfform a form mal tracheostomy forr failure to o veentilate situ uations. Th he procedu ure takes tiime and sk kill and is aassociated with a siignificant complicatio c on rate. Q Q. What ar re the com mplicatio ons of per rforming needle cr ricothyro oidotomy and tran nstrachea al ventilattion? A.. Bleeding in nto the lower airways, oesophagea al perforatio on, pneumoothorax, pn neumomediiastinum, pneumoperi cardium are all possiblle. Howeverr the main co omplication ns relate to ventilation v rrather than insertion. It I is essentiaal that the needle n orr minitracheeostomy is in i the midliine and air is i aspirated d before ven ntilation is co ommenced. The cannulla can kink or be displa aced into th he subcutan neous tissues reesulting in subcutaneou s us emphyseema. If the glottis g is nott open then n expiratory ob bstruction will w occur with w severe b barotrauma.

W Wong DT, La ai K, Chung FF, Ho RY.. Cannot inttubate–cannot ventilatte and difficu ult intubatio on strategiees: results of o a Canadia an national ssurvey. Anestth Analg 2005; 100(5):: 1439–1446 6. PMID 158 845702

Lia aise with an anaesthesio ologist perfforming tran nstracheal iinjections fo or aw wake tracheeal intubatio ons. If you ccan practicee with the te echnique, itt will allow you y to atttain familia arity and ap ppreciate thee ‘feel’ of th he loss of ressistance on insertion of the neeedle.

[45]

Task 4 4. The difficultt airway:algoriithms & adjun ncts to manage ement

E Extubatio on of th he difficu ult airwa ay

Co ooper RM. The T use of an a endotraccheal ventila ation cathetter in the m managementt of diffficult extubations. Can n J Anaesth 1996; 43(1)): 90–93. PM MID 86656 644

Exxtubation of the diffiicult airwayy can resullt in signifiicant morbbidity to the paatient. Eacch airway operator o is recommen nded to hav ve a pre-foormulated sttrategy for extubating g the difficcult airway. Iff swelling of o laryngea al/pharyng eal structu ures has been a factorr in the deevelopmen nt of the diffficult airw way, the airrway may occlude o aftter extubattion. W With the tra acheal tube e in situ an nd a breath hing circuit attached, deflate the e cuff an nd apply manual m positive presssure to the circuit (a ‘leak test’). Does this prroduce thee expected leakage intto the oral cavity around the traacheal tube? If no ot, it is pro obable thatt extubatio on will lead d to furtherr airway/brreathing diifficulties. Before defflation of th he cuff, enssure that secretions llocated abo ove the cu uff have beeen suction ned in ordeer to preven nt pulmonary aspirattion. A Airway ex xchange catheter c Seeveral hollow flexible e airway exxchange ca atheters are e available which allo ow veentilation either e by je et ventilatiion or insufflation of oxygen. Th he catheterr is pllaced throu ugh the tra acheal tubee ensuring that the en nd of the caatheter is above a th he carina. The T tracheal tube can n then be removed following a ssuccessful ‘leak teest’. The styylet may re emain in siitu until th he patient is free from m the need for po ossible rein ntubation. Q Q. What ar re the sid de effects of jet ven ntilation through t tthe airwa ay ex xchange catheter? c ? A.. The main and most dangerous co omplication n is barotrau uma resultiing in tensio on pn neumothora aces. This iss particularlly likely if th he tip of the e catheter iss below the carina. Th he catheter may move whilst in pllace and ma ay move into o the oesoph hagus.

[46]

Task 5. Pitfalls in airway management

5. PITFALLS IN AIRWAY MANAGEMENT While critical care entails multi-organ support, its every day ‘smooth’ provision is very dependent on the patency of the airway and the functionality of artificial airways. When working well, care is relatively straightforward but a difficulty in this area will destabilise management and threaten the patient very quickly. Familiarity with airway pitfalls and their rectification is a key critical care skill.

Ineffective breathing despite artificial airway This problem is diagnosed by the presence of ongoing dyspnoea, hypoxia and/or unresolving or worsening hypercarbia. Potential aetiologies include: 1. Airway is still partially/completely obstructed 2. Depressed respiratory drive 3. Inefficient respiratory effort 4. Abnormal pulmonary physiology. The first step here is to check the airway and follow the steps as described in Task 3. If the airway is unobstructed and the patient's condition does not improve, then conditions 2, 3 or 4 (listed above) apply. All require the initiation of manual ventilation prior to a more permanent solution. This may involve the use of mechanical ventilation and the use of PEEP. Q. What conditions may be associated with inefficient (spontaneous) respiratory effort? A.     

Splinting – fractured ribs, pain, abdominal distension. Muscle fatigue/weakness: tachypnoea, neurological deficit, myopathy, myasthenia gravis, polyneuritis. Parenchymal lung disease: COPD, oedema, fibrosis. Pleural disease: (tension) pneumothorax, large haemothorax or effusion. Respiratory depression: intoxication/narcotics, brain injury.

For discussion of the control of normal respiration – see PACT module on Respiratory failure For information on mechanical ventilation and PEEP see PACT module on Mechanical ventilation.

Ineffective manual mask ventilation despite artificial e.g. oropharyngeal airway   

Airway is still partially/completely obstructed Poor seal with mask/poor manual ventilation technique Abnormal pulmonary physiology.

Again the correct strategy is to go back to the airway. Is it clear? If this is in doubt, a definitive airway (e.g. orotracheal tube) will be required after attempting to improve oxygenation/CO2 removal with more effective mask ventilation. [47]

Task 5. Pitfalls in aairway manage ement

To o achieve the t latter:    

Check/readjustt airway an nd patient head h position b handss to provid de seal betw ween face and a mask ((second perrson to Use both proviide positive e pressure on bag) Get someone s with w more aairway expeerience – if readily avvailable Increease FiO2 (tto 1.0) and d fresh gas flow to 15– –20 l/min..

W When oxygeenation and d CO2 rem moval is jud dged satisfa actory or beest possiblle, trracheal intu ubation sh hould then be attemptted. If orall/nasal intu ubation is not po ossible theen a surgica al airway s hould be obtained. o

O One-side ed intubation an nd ventilation Th he distancee from the vocal cord ds to the biifurcation of o the trach hea (carina a) in th he average adult is 11–12 cm. Th he tip of an n 8.0 (adullt) tracheall tube is typ pically 6..5 cm below w the uppe er surface o of the ballo oon. Thus, even if thee upper surrface of th he balloon is almost touching t th he lower su urface of th he vocal corrds, there is just ovver 5 cm beetween the e tip of the tracheal tu ube and th he carina. Itt is therefo ore qu uite easy to o inadverte ently placee a tracheall tube so th hat the tip llies beyond d the caarina. In ad dults with normal bro onchial an natomy, the e tube tip w will usually y (but no ot always) pass into the t right m main bronch hus.

O One-sided in ntubation and ventilaation may be diagnossed by ausccultation of o the ch hest immed diately afte er intubati on. Absentt or diminiished breatth sounds//air en ntry in onee hemithorax (particu ularly on th he left side e) should su uggest bronchial in ntubation. This T may be b supportted by a nu umber of otther signs. Q Q. In a pattient with h unilaterral breath h sounds after placcement of a tr racheal tu ube, whatt other fin ndings would supp port the d diagnosis s of unilateral (usually right side ed) bronc chial intu ubation? A..      

Reduced expansiion of (left) hemithorax. (Sligh htly) reduce ed oxygen saaturation on n oxymetry (SpO2). Requiirement forr high FiO2 tto maintain n normal SpO2. Excesssive tube le ength passeed as judged d by tube ma arkings at teeeth/lips. Reduced complia ance on maanual ventila ation (‘stiff lungs’). High inspiratory y pressure an nd/or poor inspiratory y tidal volum me if using mech hanical ventiilation.

n is suspeccted, deflatte the trach heal tube cu uff and slo owly Iff bronchial intubation w withdraw th he tube 1–2 2 cm. Re-in nflate the cuff c and ma anually ven ntilate the patient w while auscultating botth sides of tthe chest. Is air entry y present aand equal? Be [48]

Task 5. Pitfalls in aairway manage ement

su uspicious iff the tube has h to be w withdrawn more than n 3–4 cm. O Observe th he tube leength mark king at the teeth. If it is much leess than the expected d correct le ength, yo ou may be dealing wiith anotherr diagnosiss (see below w).

Vissit the opera ating theatrre/room and d request to o auscultatee the lungs of o paatients on manual m or mechanical m p positive preessure ventillation. Becoome familia ar with wh what normal air entry in n this situatiion sounds like. Would d you be ablle to detect un nilateral inttubation? How H quicklyy would you be able to make m that ju udgment?

Q Q. Excludiing bronc chial intu ubation, liist other causes c off actual or r ap pparent unilatera u al ventilattion? A..          

Pneum mothorax Tensiion pneumo othorax Haem mothorax/plleural effusiion Broncchial obstru uction n Trach heobronchia al disruption Unila ateral parenchymal diseease olidation/a Pulmonary aspirration/conso atelectasis Unila ateral pulmo onary bulla//emphysem ma Previo ous pulmon nary surgeryy (pneumon nectomy/lob bectomy) Previo ous pulmon nary tubercu ulosis.

T Tube obs struction n A patient wiith an obsttructed tub be will exhiibit obstruccted breath hing patterrn (see Taask 1 ) and d other clin nical signs o of severe acute a respirratory distrress – dysp pnoea, hyypoxaemia a, hypercarrbia. If the patient is receiving mechanical m al ventilatio on, one orr more alarrms may be triggered d e.g. high inflation pressure p orr poor (exh haled) tid dal volumee. Failure of o oxygen/aair supply to the venttilator mayy produce the t saame clinic cal finding gs as tracheeal tube ob bstruction but b a differrent alarm prrofile. If in n doubt che eck gas sup pply connections, ven ntilator fun nction and veentilator-to o-patient circuit. c T Tracheal tube t obsttruction Th he causes of o an obstrructed traccheal tube are: a     

Kink in trachea al tube Mucu us plug/blo ood/secrettions Narro owed lume en in non-rreinforced nasotracheal tubes Biting, particularly with (w wire spirall) reinforce ed tubes w which becom me perm manently de eformed wh when comprressed (see e anecdote below) Obstrruction of tube tip byy side/postterior wallss of lower aairways.

Al Always go back b to simple techniq ques. Use a manual bagging b syystem (ofteen termed an ‘anaesth hetic’ or ‘p physiothera apy’ circuitt) to o manuallyy ventilate the t patientt – particularly those e whose reespiratory difficulty has h arisen w while on mechanical m [49]

Task 5. Pitfalls in aairway manage ement

veentilation. High resisstance/inab bility to infflate the lu ungs suggesst tu ube obstrucction. The (recent) in nability to pass p a sucttion caatheter dow wn the lum men is also highly sug ggestive esp pecially in lo ong-term ventilation v patients. I n the non--emergency y situation n, a small fibree optic bronchoscopee may be pa assed down n the tube to o visualise the nature e and site o of the obstrruction. Sometimes aan ob bstruction can be rem moved (e.gg. by suction catheter)). So ometimes it requires removal o of the tube,, manual ventilation (tto reverse hypoxaemi h ia and hypeercarbia), followed by b reeintubation n. The latte er may be d difficult du ue to vocal cord (and geeneralised airway) oe edema. App propriate preparatio p ns should bee made. Seee the video o demonsttration belo ow.

A second intuba ation in a patient who hass required prolonged p tracheal intu ubation is often sign nificantly more difficult than the original procedure p

A neu urosurgicaal patient, in i ICU, started to bitee on his reiinforced trracheal tub be when hiis sedation n was reducced. Suctio on catheterrs could still be p passed fullyy into the trachea t witth slight difficulty. Tw welve hourrs later the patient su uddenly beecame disttressed and d the ‘high pressure’ and ‘low exxhaled min nute vvolume’ ala arms sound ded on the ventilator. Manual bagging b waas unhelpfu ul due to vvery high reesistance and a the pattient’s SpO O2 fell quick kly to 82%.. The trach heal tube w was removeed and repllaced by a standard (non-armo ( oured) trach cheal tube. E Examinatio on of the orriginal tubee showed a severely narrowed n ssection wh here the w wire spiral had h been crushed c byy biting. Th his segment was comp pletely obsstructed b by a plug off clot, fibrin n and pulm monary seccretions.

T Tracheosttomy tube e obstruc ction Caauses:  

Plugg ging Abno ormal posittion within n the airwa ay. [50]

Task 5. Pitfalls in airway management

Tracheostomy tubes are shorter, more curved and more rigid than tracheal tubes. They rarely kink. They may become blocked with secretions/blood but often suctioning the tube easily solves this. Tracheostomy tubes with inner cannula have an advantage in this regard in that when blocked, the inner cannula (containing the obstructing plug) may be removed for washing, leaving the outer cannula in situ providing a clear airway. Such tubes are especially advantageous for critical care patients discharged to general wards. Tracheostomy tubes may become obstructed when the distal opening becomes tightly applied to the side/posterior walls of the trachea or (rarely) the carina. Often problems with tracheostomy tubes are related to partial or complete displacement, which may be surprisingly difficult to detect.

Tube displacement Tube displacement often constitutes a life-threatening emergency. Although it may be viewed as ‘bad luck’ or ‘an unavoidable accident’ this is often not the case and such adverse events should be viewed as avoidable. The frequency of tube displacement should be reduced by good medical and nursing practices (see below). Tracheal tubes The first step in management of tube displacement is to decide whether the patient can manage without the tube (see Tasks 1 & 2). If replacement of an orotracheal tube is required, appropriate preparation for a difficult intubation is strongly advised (see above). Tracheostomy tubes Tracheostomy tubes are usually more secure than tracheal tubes but, if displaced, may result in a very difficult situation. This is particularly so if the tracheostomy was performed less than 5–7 days previously and if the tracheostomy has been performed as a percutaneous technique. Again the option to leave the patient without a tube should be considered. If this course is pursued, and the acute concerns regarding oxygenation and ventilation have passed, the tracheostomy opening should be dressed to make it as ‘airtight’ as possible. This will facilitate more effective coughing. If the tracheostomy is new (less than 5–7 days old), the track through the various layers of tissue in the neck may be lost, preventing simple replacement of the tube. Occasionally a gum elastic bougie is helpful in routing the tracheostomy tube back into the trachea through the (now disappeared) openings in the tissue plains of the neck. Such attempts should NOT be prolonged. Often it is simpler and safer to reintubate the patient with an orotracheal tube (see above). After reintubation, the tracheostomy should be sealed with an appropriate dressing and the tracheostomy procedure repeated electively later. With a more mature tracheostomy (more than 7 days old), it is often a simple matter to place a new tube through the mature (stable) track which forms between the skin and the trachea.

[51]

Task 5. Pitfalls in airway management

Another problem is that tracheostomy tubes may be displaced from the lumen of the trachea but appear to be in the ‘normal’ position when viewed externally. Any problem with breathing, ventilation or tracheal suctioning in patients with a tracheostomy must be considered seriously. Pre-emptive fibre optic assessment of the tube position and patency may be very useful. Sometimes if required the endoscope can be used to ‘railroad’ the tracheostomy tube back to the optimum position. Sometimes the best course of action is to remove the tracheostomy tube and reintubate as described above. Q. What situations increase the risk of tracheal or tracheostomy tube displacement? A.      

Insufficient numbers of appropriately trained nursing staff. Agitated patients/poor sedation. Failure to place tracheal tube in mid-trachea/tracheal tubes cut inappropriately short. Insecure/inappropriate tracheal tube fixation. ‘Drag’ on tracheal tube e.g. failure to support ventilator circuit. Major movements of patient – physiotherapy, proning, moving to other bed/trolley/operating table without appropriate care/stabilisation of the tracheostomy tube.

CONCLUSION Appropriate management of the airway is the cornerstone of good resuscitation. It requires good judgment (airway assessment), skill (airway manoeuvres) and constant reassessment of both the patient’s condition and the efficacy of medical interventions. While complex procedures are sometimes life-saving and always carry the ability to impress the uninitiated, it is important to realise that the timely application of simple airway manoeuvres are often very effective and may avoid the need for further intervention.

[52]

Self-assesssment

SELF F-ASSES SSMEN NT EDIC--style Typ pe K 1. How w can you u clinically differen ntiate at the t bedside betwe een strido or and bronch hospasm m? A. S Stridor is mainly m insp piratory B. B Bronchosp pasm is besst heard in n the end in nspiratory phase C. R Respiratorry rate is ch haracteristtically low in patientss with strid dor D. S Stridor is best b heard through a stethoscop pe 2. If th his man (see picture) requiired ‘inva asive’ venttilation (u using a trache eal tube), what pro oblem wo ould you anticipate a e? A. D Difficulty with w bag an nd mask veentilation B. D Difficult trracheal intu ubation C. H High risk of o aspiratio on D. C Corneal da amage

portant stteps to as ssure succcessful aiirway ma anagemen nt (intuba ation) 3. Imp includ de: A. E Elevation of o the head d (occiput)) B. F Flexion of the atlanto o-occipitall joint C. S Skilled asssistance D. E Ensuring that t a straight larynggoscope bla ade is used 4. Com mplication ns follow wing the u use of an orophary o yngeal airrway inclu ude: A. G Gagging B. V Vomiting C. L Laryngosp pasm D. W Worsening g airway ob bstruction 5. Wha at are the e importa ant determ minants of o the acttual inspiired oxyge en concen ntration in i a patie ent using a face-mask? A. O Oxygen flo ow to the mask m B. P Patient pea ak inspirattory flow raate C. P Patient resspiratory ra ate (frequeency) D. T Tidal volum me

[53]

Self-assessment

6. Indications for tracheal intubation include: A. Obstructed airways B. Inadequate ventilation or oxygenation C. GCS <8 D. Severe metabolic acidosis 7. Usual methods of ensuring optimal positioning for a tracheal tube in adults is to check that: A. Upper limit of the cuff is 1–3 cm below the vocal cords B. Lower limit of the cuff is 5–6 cm below the vocal cords C. End of the tube is as close as possible to the carina D. End of the tracheal tube is 3–4 cm above carina 8. An adult patient in the ICU is still hypoxaemic after a successful intubation of the trachea and, on auscultation, you think the breath sounds are diminished on the left side. What other (bedside) findings would support the diagnosis of unilateral bronchial intubation? A. Reduced expansion of left hemithorax B. PaCO2 more than twice normal values C. Tube length 19 cm at the teeth D. High FiO2 to maintain normal SpO2 9. You suspect a partial tracheal tube obstruction in one of your ICU ventilated patients because of a gradual increase in airway resistance. What would you do to confirm your suspicions? A. Rule out non-endotracheal tube causes by taking a chest X-ray B. Immediately reintubate the patient C. Regard the successful passing of a suction catheter as evidence that partial tube obstruction can be ruled out D. Perform a bedside bronchoscopy EDIC-style Type A 10. The inability to open up the mouth, after administration of anaesthesia drugs to facilitate tracheal intubation, could be caused by all of the following EXCEPT: A. Masseter muscle spasm B. Facial burns C. Scleroderma D. Oral albinism E. Post radiation fibrosis 11. Drugs to facilitate rapid (sequence) endotracheal intubation may include the following EXCEPT: A. Propofol B. Thiopentone C. Alfentanil D. Suxamethonium E. Pancuronium [54]

Self-assessment

12. Important factors for a fibre optic intubation include all of the following EXCEPT: A. Placing the tracheal tube on fibrescope prior to procedure B. Use of topical anaesthesia in nasopharynx C. Induction of general anaesthesia prior to procedure to avoid coughing D. Endoscopic identification of the tracheal rings E. Having a skilled assistant at hand 13. A 73-year-old female requires intubation prior to mechanical ventilation because of intracerebral haemorrhage and GCS of 5. After light sedation, and use of topical anaesthesia, you are not able to visualise the epiglottis or vocal cords, and two attempts to blindly pass the tube are unsuccessful. During the second attempt her oxygen saturation (SpO2) has fallen from 97 to 82%. Which of the following procedures would be the most appropriate next step: A. Immediately ask for the intubating bronchoscope in order to perform a fibre optic intubation B. Ask for a laryngeal mask C. Immediately give muscle relaxation to facilitate intubation D. Perform an emergency cricothyroidotomy E. Withdraw the laryngoscope and assist her spontaneous ventilation efforts with mask and bag 14. The major indication for performing a cricothyroidotomy is: A. If two or more different methods to perform intubation are unsuccessful B. In patients with inability to move the neck C. ‘Cannot intubate, cannot ventilate’ situation D. If the physician in charge is inexperienced in intubation E. A patient with micrognathia 15. The best method to confirm the tracheal positioning of an endotracheal tube is: A. Reported visualisation of the tube entering through the vocal cords B. Chest wall movement during positive pressure ventilation C. Auscultation of the lungs D. An end-tidal CO2 measurement or trace E. The presence of water vapour condensing in the breathing system (circuit)

[55]

Self-assessment

Self-assessment answers Type K Q1.

Q2.

Q3.

Q4.

Q5.

Q6.

Q7.

Q8

Q9.

A. T

A. F

A. T

A. T

A. T

A. T

A. T

A. T

A. T

B. F

B. T

B. F

B. T

B. T

B. T

B. F

B. F

B. F

C. F

C. F

C. T

C. T

C. F

C. T

C. F

C. F

C. F

D. F

D. F

D. F

D. T

D. T

D. F

D. T

D. T

D. T

Type A 10. Answer D is correct 11. Answer E is correct 12. Answer C is correct 13. Answer E is correct 14. Answer C is correct 15. Answer D is correct

[56]

Patient challlenges

PATIIENT CH HALLEN NGES An 18--year-old obese man is invo olved in a (witness sed) road d traffic accide ent. He wa as the drive er of a car o observed crashing c into a wall at approxim mately 80 km//hr. He wa as not wearring a seat belt and was w ejected 10 m from m the car. He H receiveed basic lifee support within w seco onds of thee accident. Five minu utes later, he h arrives in the Em mergency Departmentt of the loca al hospital. His eyes aare not open, he is makiing incomp prehensible sounds aand he is fleexing to pa ainful stim muli. His respiraatory rate iss 30 breath hs/min and d breathing is noisy. He is cyan nosed and has h a heart raate of 120 bpm b and blood b presssure 100/6 60 mmHg. Q. Whaat immedia ate action should s be ttaken? A. Firstt an immed diate assesssment of aairway and d breathing g must be p performed and oxygen n given. In view v of the e mechanissm of injurry it must be b assumed d that the patient p has an unstable cervical c spine. Protecttion of the cervical sp pine whilstt performin ng any airway manoeuvrre is param mount. Look k and listeen for signss of airway obstructio on. Observve the respiiratory rate e, the patteern of chesst movement and thee presence of o retractiion of the suprastern s nal, supracllavicular and intercostal musclees. Ausculttate for bilateraal chest sou unds.

Assessm ment of thee airway Cervicaal spine injury The pattient is tacchypnoeic and a has siggns of partiial airway obstruction n. Whilst avoidin ng neck exttension, yo ou attempt to open th he mouth and a elevatee the jaw. Supplemental oxyygen by tig ght fitting fface-mask is provided d and a cerrvical colla ar is fitted.

Variablle flow facee-mask he triple airrway mano oeuvre indiicated? Justify your decision. d Q. Is th A. The triple airw way manoeu uvre involvves openin ng the mouth, elevatin ng the man ndible and exttending thee neck. Wh hile it may help to alleviate obsttruction off the airway y, in this casse, neck ex xtension mu ust be avoiided since there may y be a cerviccal spine in njury involveed.

Triple aairway man noeuvre d with the insertion of o an oroph haryngeal aairway and d The airrway has beeen cleared oxygen n is being provided p by y a tight fittting face-m mask. How wever the paatient beco omes apnoeicc. There is no respon nse to deep p painful stiimuli. You note clearr fluid com ming from th he nostrils.. Whilst preparing fo r intubatio on manual ventilation n with a ba agmask iss commencced.

[57]

Patient challlenges

Orophaaryngeal aiirway ation Bag-maask ventila Q. Whaat preparattion should d be made prior to in ntubating th he patient?? A. Prep pare the patient p by y reassessiing the airw way. Positiion the pattient optim mally. Ensuree sufficient intravenous access. Prepare all equ uipment including i a range of tracheal t tubes, larynggoscopes and a emergeency airwayy equipme ent. Prepare the dru ugs includ ding anaestthetic agen nts, muscle e relaxantss, vasopresssors and ressuscitation n drugs. Prepare your assistant. a The patien nt may hav ve a full sto omach and d so an assiistant to perfo orm cricoid d pressure is required d. In view of the pote ential cerviical spine injury, i this is b best perforrmed as bim manual con ntrol of thee neck. A dedicated d ((additionall) assistan nt to perfo orm manua al in-line sttabilisation n is manda atory.

Prepariing for intu ubation Cricoid d pressure and a BURP P Manuaal immobiliisation – PACT P modu ules on Mu ultiple trauma and Paatient transpo ortation Prep paration iss the key to o successfu ul intubatio on. Q. Whaat is the preferred me ethod of traacheal intu ubation in this patien nt? Why? What W would yyou do with the cerviical collar?? A. Orall intubation n with man nual in-linee stabilisattion of the cervical sp pine is the preferrred option. Nasal intu ubation is ccontraindicated beca ause of apn noea – with hout breath sounds, it would be unlikely u th hat a ‘blind’ technique e would bee successfu ul and insertin ng a nasal tube t underr direct vission at lary yngoscopy has h no advvantages ov ver oral intubattion. The presence p off possible C CSF leakag ge suggests basal skulll fracture which w is also a contraind dication to o nasal intu ubation. Th he anteriorr portion off the cerviccal collar sshould be removed/r r eleased to allow mou uth opening and the aapplication n of cricoid pressure. Manual in n-line immo obilisation n must be employed. e IIn some ha ands, the usee of a stylett within the e tracheal ttube may improve i th he chances of a successsful intubattion at the first attem mpt.

Types o of intubatio on

[58]

Patient challlenges

w you administer a r prior to in ntubation? ? Which mu muscle relax xants Q. Whiich drugs would (neurom muscular blocking b drrugs) are aappropriatee and whatt are the poossible side e effects of the drug gs? A. The patient is unconsciou u us and nott respondin ng to pain so s hypnotiic drugs ma ay not be requ uired. Cauttion should d be taken to avoid riises in intra acranial prressure asssociated with in ntubation in n this patie ent with po otential inttracranial pathology. p Many exp perts would ggive a judiccious dose of an anaeesthesia induction ag gent such aas propofoll. A musclee relaxant should s be administer a red. Suxam methonium (succinylccholine) remains a safe cchoice for a rapid onsset short accting depollarising mu uscle relaxxant; howev ver the potentiial side effeects includ de tachycarrdia and hy ypertension n due to au utonomic stimulaation or bra adycardia following h higher dosses. Skeleta al muscle ccontraction n can result in high intrraocular prressure, inccreased inttragastric pressure, p m myoglobinuria, and hyp perkalaem mia. Intracrranial presssure may also a be incrreased. On balaance, in this case, it is decided tto use suxa amethoniu um 100mg – given as an intraveenous boluss.

Use of d drugs in aiirway management Bew ware of the potential ccardiovasccular side effects e of in ntravenouss an naesthetic agents in trauma t pattients who may be hy ypovolaem mic.

Feeneck RO, Cook C JH. Fa ailure of diaazepam to prevent p the suxamethon s nium inducced rise in n intra-ocullar pressuree. Anaesthessia 1983; 38 8(2): 120–1227. PMID 68298 877 Laavery GG, McGalliard M JN, J Mirakh hur RK, Shep pherd WF. The T effects of atracu urium on in ntraocular p pressure durring steady state anaessthesia and rapid sequence in nduction: a comparison with succcinylcholinee. Can Anaessth Soc J 19 986; 33(4): 4 437–442. PMID P 37556 640

Your beest laryngo oscopy atte empts reveeal the view w above witth no visuaalisation off the larynx. You makee one attem mpt to passs a gum ela astic bougie e ‘blindly’ iinto the tra achea withou ut success. You Y are ab ble to manu ually ventillate the pattient with 1100% oxyg gen but the oxyygen satura ation is gra adually fallling to 94% %. [59]

Patient challlenges

Assessm ment of thee airway Q. Desccribe the view. What options arre now ava ailable? A. The view is desscribed as Cormack aand Lehanee grade 4 (of a 1 to 4 scale of im mpaired visualissation of la arynx). Thiis situation n is an exam mple of ‘faiilure to inttubate but able to ventilatte’. This sittuation can n rapidly d deteriorate to the ‘faillure to intu ubate–failu ure to ventilatte’ if an ina appropriatte course off action is chosen. Un nlike a pati tient anaesth hetised forr an elective surgical p procedure, the option n to attemp pt to awak ken this patientt is not ava ailable. Q. Whaat do you do d next? Ou utline yourr sequence of responsses. A. Call for more experience e d help. Ensuree optimal patient p posiitioning. Choosee from adju uncts which h include tthe gum ela astic bougiie (alreadyy tried), alternaative laryng goscope bla ades, lighteed sylet or video lary yngoscopy. Practitiioners shou uld use one or two off these adju uncts – it is i not advissable to try y each in turn! If this ffails to imp prove the view v then aavoid repea ated attemp pts at intubbation. Mo ove on to the n next step on the difficcult airwayy algorithm m. Insert a laryngeall mask airw way or intu ubating LM MA. Fibre o optic intuba ation can be b considerred only if the operattor is experrienced. If thesee manoeuvvres fail or are inapprropriate, co onsider cricothyroidootomy.

Co ormack RS,, Lehane J. Difficult traacheal intub bation in ob bstetrics. An naesthesia 1984; 39(11): 110 05–1111. PM MID 650782 27 Liink to http:///www.nda a.ox.ac.uk/w wfsa/html/u u09/u09_0 025.htm

Difficullt Airway Algorithm A Larynggeal mask airway a Fibre o optic intuba ation hyroidotom my Cricoth Fibre o optic intuba ation is perrformed an nd the traccheal tube is i inserted d. Oxygen saturattion is 100% % and air entry e is heaard bilaterrally.The po osition is cchecked using the fibre op ptic scope, the trache eal tube is ssecured an nd the patie ent is transsferred to the t intensivve care unit. Ten min nutes later the oxygen n saturatio on falls to 8 80%.

[60]

Patient challlenges

Avo oid repeate ed attemptss at intuba ation if noth hing has occcurred to po otentially improve i in ntubating cconditions. This may result in in ncreased trrauma, aiirway swellling/oedem ma and thee likelihood d of furtherr complicaations. Q. Whaat is the mo ost likely cause c of thiis fall in ox xygen saturration? A. A freequent cau use of decre eased oxyggen saturattion followiing intubattion is mov vement of the ttracheal tub be followin ng (approp priate) inseertion. The tube may be in eithe er main bronch hi or may have h been displaced d in nto the oessophagus. Q. How w may the diagnosis d be b confirm med? A. Checck for end--tidal CO2 or o identifyy the tube ly ying in the e trachea byy endoscop py. This will con nfirm that the tube iss within thee airway. The T chest should be ccarefully examin ned to assess air entry y and expaansion. Thiis may sugg gest endobbronchial intubattion which should be corrected immediately. Be awa are that thee signs ma ay be mislead ding. The fact f that th he tube had d previouslly been in the t correctt position does d not rulee out subseequent mo ovement esspecially in n the traum ma situation n. A chest X-ray X should be perform med to con nfirm tube position.

Correctt tube posiitioning End-tid dal CO2 mo onitoring Mislead ding signs of tube pla acement The traacheal tubee has been misplaced d into the riight main bronchus b iin this case e. This occurs more often n in the diffficult airw way. The rellief of actu ually securiing the airw way can lead to the tube being b positiioned furth her into the trachea than t requirred.

Q. Whaat are the other o poten ntial causess for a fall in oxygen saturation n at this sta age? A. Therre are man ny potential causes fo or the fallin ng oxygen saturation s including:: Pneum mothorax orr massive haemothor h rax Aspirattion of gasttric conten nts or blood d from the upper airw way Pulmon nary contu usion Pulmon nary oedem ma Airwayy plugging [61]

Patient challlenges

After th hree days in i the inten nsive care u unit the cu uff on the trracheal tubbe develop ps a leak. Th he patient requires PEEP P of 7.55 cmH2O and FiO2 off 0.5. Q. How w would yo ou change the t tracheaal tube and d what preccautions wo would you ta ake? What aare the poteential side effects of tthe method d used to change c the tube? A. Thiss patient ha as both a ce ervical spin ne injury and a a difficcult airwayy. It is not approp priate to rem move the tube t and asssume thatt reintubattion will bee straightfo orward even wi with the aid of fibre op ptics. Reinttubation may m be morre difficult given the possibiility of cord d/airway oedema. Co onsider cha anging the tube over a gum elasstic bougie or airway exchange (ventilatin ( ng) catheterr. Be aware e of the posssible side effect of tensiion pneum mothorax esspecially iff the tip of the tube ch hanger is p positioned below the cariina. Prepare for a forrmal tracheeostomy orr at least a cricothyrooidotomy in the event o of failure to o secure the airway.

Changiing the traccheal tube hyroidotom my Cricoth piratory function imp proves slow wly but he remains neeurologica ally The pattient’s resp obtund ded with a Glasgow G co oma scale o of 7. ICP monitoring m and repeaat CT scan fail f to show evvidence off intracraniial hyperteension but the t CT app pearances d do suggestt a significcant cerebrral hypoxicc injury. Byy day ten fo ollowing in njury, he iss on 40% ox xygen, CPAP 3 cmH2O with w PS 10 cmH c 2O.

See Glaasgow Com ma Scale in the PACT module on n Traumatic brain injjury a for perform ming a tracheostomy y and when n do you th hink the Q. Whaat are the arguments optimaal timing sh hould be? A. Therre remainss some debate in inten nsive care medicine over o the toopic of tracheo ostomies. This T patien nt has suffeered a significant hea ad injury reesulting in an alteratiion in levell of conscio ousness. H He also conttinues to require add ditional ventilattory suppo ort. Prolong ged translaaryngeal in ntubation may m result in larynge eal or subglotttic damag ge. A trache eostomy m may (i) imprrove broncchial toilet,, (ii) provid de a more seecure airw way and (iii) be betterr tolerated than an orrotracheal ttube.

Indicattions for tracheostom my

[62]

Patient challlenges

Q. Outlline the diffferent metthods of peerforming a tracheostomy and yyour preferred choice in this casee? A. Traccheostomy may be pe erformed b by several percutaneo p ous techniqques or a su urgical tracheo ostomy ma ay be performed. Thee identified d relative co ontraindicaations to percutaaneous traccheostomy y in this paatient inclu ude the presence of a cervical sp pine injury aand the diffficult airw way. Other iimportant factors incclude the p possibility of o bleedin ng, further anatomica al abnormaalities and the experience of thee operator.. These factors are becom ming less crritical with h the greateer experien nce in the p performancce of percutaaneous traccheostomies.

Percutaaneous tracheostomy y A surgiical tracheo ostomy is performed p d in the opeerating theatre/room m and the patient is returrned to thee intensive care unit. On transfeerring the patient p fro m the porttable transpo ort ventilattor to the intensive caare ventila ator, you no ote that thee peak insp piratory pressurre is over 40 4 cmH2O.. There app pears to bee little chesst movemen nt and air entry appears to be red duced on bo oth sides o of the chestt. The saturration fallss from 99% % to 90%.

omy Compliications off tracheosto p cau uses of thiss fall in satturation. Outline O a syystematic Q. Desccribe the possible approaach to confiirm or excllude them?? A. Go b back to firsst principle es – A,B,C. Is the tracheostom my tube in n the tracheea? Check for f end-tid dal CO2. Plaace the pattient on baggingg circuit (b breathing system) s to oxygenate with 100% % oxygen. H How does it i feel? What iss your imp pression of chest com mpliance? Has H the tub be moved in nto a main n bronch hus? Look for f bilatera al chest exp pansion an nd listen for bilateral air entry. If I there is any d doubt rega arding the position p off the tracheeostomy, th he position n should be e checked d with fibrre optic bro onchoscopyy. Does th he patient have h a pne eumothoraax? A Chestt X-ray is the investiggation of ch hoice. Air entry may be decreased and the trrachea deviiated away y from the sside of a te ension pneum mothorax. Look L for sig gns of subccutaneous emphysem ma. If a tenssion pneum mothorax ha as occurred d, immediaate decomp pression with w a 14G ccannula in the 2nd inttercostal sp pace (mid--clavicular line) is req quired follo owed by a d definitive thoraciic drain. Has haaemorrhagee into the airway a occu urred? Thee airway sh hould be su uctioned an nd a fibre op ptic inspecction perforrmed. The position of th he tracheosstomy was checked by b fibre opttic endoscoopy. The tracheo ostomy wass too shortt and its po osition wass such that the distal opening was w occludeed by the posterior p trracheal walll. Althoug gh a standa ard tracheoostomy may be suitablee for the majority m of patients p th here are some patientts where prroblems ca an occur. A tracheosstomy with h an adjustaable flangee was reinserted and positioned d optimaally using fiibre optic endoscopy e y. [63]

Patient challenges

On reflection, the patient has many complications of management of the difficult airway. The above scenario may have been due to the patient coughing against the tube or due to bronchospasm. Some of the complications such as the endobronchial intubation were avoidable. There are numerous complications of tracheostomy ranging from minor haemorrhage to death. Pneumothorax and pneumomediastinum are not uncommon and should be considered early in a situation such as this. Tension pneumothorax can be fatal if not treated rapidly. Tracheostomy tubes may be misplaced into the anterior mediastinum resulting in massive subcutaneous emphysema or may be occluded by the posterior tracheal wall or at the carina. There is no doubt that the secret of success in managing the difficult airway lies in becoming skilled in a wide range of techniques. Ensure that you update your skills on a regular basis. If one technique fails, move on to the next stage of the algorithm rapidly. Avoid the temptation to use increased force and neck extension especially in this case where there is potential to cause or exacerbate a spinal cord injury. Seek more experienced advice early. Always ensure that oxygenation is maintained and have the necessary equipment readily available to perform a trans-tracheal puncture, by needle or other cricothyroidotomy approach, in the ‘failure to intubate– failure to ventilate’ scenario.

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