Fibreoptic_intubation_Update_2011.pdf

7/27/2019 Fibreoptic_intubation_Update_2011.pdf

1/8

Fibreoptic intubation

Sarah Barnett*, Irene Bouras, Simon Clarke*Correspondence email: [email protected]

INTRODUCTION

Awake breoptic tracheal intubation is a valuabletechnique that achieves sae airway management opatients who have known or potential difcult directlaryngoscopy. It is a skill in which most anaesthetistswould like to be procient, however, due to aperceived lack o opportunities, a large proportion arenotcondentinperformingthistypeoflaryngoscopy.

Fibreoptic intubation can be perormed on awake oranaesthetised patients. An awake technique is chosen

when it is considered unsae to anaesthetise the patientbeore guaranteeing the ability to secure their airway,usually when difcult laryngoscopy and difcult bag-mask ventilation are expected. able 1 shows the vitalsteps in this procedure.

AnaesthesiaUpdate in

Summary

Awake fbreoptic intubationis a useul techniquewhere dicult intubationis anticipated on the basisofairwayexaminationor previous anaesthesia.Intubating fbrescopes arenot universally available,but are increasinglyound in resource poorsettings as donated

equipment. The indications,contraindications,equipment and preparationrequired or awakefbreoptic intubation arediscussed. Sedation isdesirable although notessential and the drugsused to achieve this dependlargely on availability.Adequate anaesthesia o theairway is essential or a saesuccessul procedure andwe describe our preerred

technique along withalternatives.

Sarah Barnett

Perioperative ClinicalResearch Fellow

Irene Bouras

Locum ConsultantAnaesthetist

Simon Clarke

Consultant AnaesthetistUniversity College London

HospitalLondon NW1 2BU

UK

ClinicalOverviewA

rticles

situationswhereitisbenecialtoassessapatientsneurological status ater intubation, but prior tosurgery, or example those with an unstable cervicalspine injury.

As with any procedure, there are contraindications to

perorming the technique, particularly patient reusalor non-compliance with the technique.

Table 2.Contraindications to awake breoptic

intubation

page 27Update in Anaesthesia | www.anaesthesiologists.org

Table 1.Ten essential steps to perorming awakebreoptic intubation

1. Ensure appropriate indication

2. Explain procedure to patient and givepremedication as appropriate

3. Prepare equipment; assemble and check fbrescope,railroad endotracheal tube (ETT) over fbrescope,prepare local anaesthetic solutions

4. Monitoring,oxygen,intravenousaccess

5. Commence sedation i being used

6. Position patient and ensure appropriate level osedation

7. Anaesthetise airway8. Perorm intubation

9. Confrm correct ETT position

10. Administer general anaesthesia

PATIENT SELECTION

e principal indication for awake breopticintubation is patient saety in the setting o adocumented history o difcult intubation and/oracemask ventilation. Other indications include:

patients at risk of aspiration of gastric contents

(unasted or severe reux) who require intubationbut are known or potentially difcult to intubate,and

Patient reusal

Inexperience

Local anaesthetic sensitivity

Non-compliance/uncooperativee.g.children,special

needs patients

Airway bleeding

Critical airway (see below)

A patient with stridor has an airway that maybecome obstructed with minimal provocation(sometimes termed a critical airway). Tis is arelative contraindication to the technique - insertionof a breoptic scope through the narrowest parto the airway may cause complete obstruction.Tereore in cases o severe upper airway obstructionalternative techniques, such as inspection under deepinhalational anaesthesia or awake tracheostomy,should be considered to secure the airway. In cases oairway bleeding, whether due to trauma or tumour, a

breopticapproachtointubationisnotadvisedasthebloodobscurestheeldofvision.

ORAL OR NASAL APPROACH

Awake breoptic intubation can be performed viathe mouth or the nose. Many anaesthetists preer thenasal approach initially, as this tends to oer an easierline o access to the larynx and it is usually bettertolerated by patients. Nasal pathology and a currentor previous history o epistaxis are contraindicationsto this route.

Te mouth has a greater volume than the nose, but

it can be easier to stray rom the midline positionwhen inserting the scope. In this situation a split oralairway (Berman or Ovassapian Figure 1) can help.


2/8page 28 Update in Anaesthesia | www.anaesthesiologists.org

Avoid oral intubation i there is major oral pathology or the tube willinterere with surgical access.

Figure 1. Berman Airway - These airways are similar to conventionaloropharyngeal airways, the diference being that they allow passage o

both the brescope and the railroaded endotracheal tube. Their design

allows them to be removed rom the mouth without dislodging the

brescope or the tube.

PREPARATION - EQUIPMENT

Ensure that prior to commencing anaesthesia your room is ullyequipped with an anaesthetic machine, suction, tilting patienttrolley, emergency drugs and equipment or cricothyroid puncture.Tis is essential to achieving smooth and efcient conduct o theawake intubation. A skilled assistant, with prior experience o thisprocedure, will be required to help you. It is also useul to have athird member o sta to support and reassure the patient during theprocedure.

Fibrescope (Figure 2)

It is important that you, as the operator, can set up the scope and

monitor. Te steps required to do this are as ollows:1. Ensure there is a unctioning light source that is compatible with thebreopticscope.

2. Focusthebreopticlaryngoscopebyvisualisingneprint.

3. Attach the camera (i you have one) and reocus the cameralens.

4. Perorm a white balance i you are using a camera.

5. Make sure that the camera is orientated correctly by ensuring the blacktriangle(orothermarkerinthevisualeldofthescope)is

at the 12 oclock position.

6. Load the endotracheal tube (E) onto scope, securing it with asmall piece o tape (Figure 3)

Figure 2.The breoptic scope

Figure 3. Fibreoptic scope loaded with north-acing Portex endotracheal

tube


3/8

Sterile gloves should bewornwhen handling the brescope.ebrescope should always be held at its most distal point (i.e. asclose as possible to the patients nose or mouth as possible) and bekeptstraighttoavoidkinkingandfractureofthebreopticstrands

contained within it. Hold the scope in your dominant hand with theleveronthecontrolbodypointingtowardsyou;inthiscongurationmoving the lever up with your thumb will move the tip o the scopedown, and moving the lever down with your thumb down will movethe tip up. Tere are three possible movements:

1. tip up/down,

2. scope inserted deeper or withdrawn,

3. clockwise/anticlockwise rotation or the scope. I the scope is keptstraight the rotation o the control end will cause exactly thesame movement o the tip

ebreopticscopeusuallyhasa1.0-1.5mmworkingchannelbutsuctioning o secretions is oten ineective through a port o sucha narrow calibre. Careul suctioning o the mouth with a Yankeursucker (or ofthe nosewith ne bore suction catheter) will often

clear secretions more reliably. Tis is generally well tolerated aterapplication o topical local anaesthetic (see later).

Endotracheal tube (ETT)

Te choice o endotracheal tube depends upon the clinical situationand tube availability. Reinorced Es are commonly used (e.g.Mallinckrodt), which can be placed orally or nasally. Te E thatcomes with the intubating Laryngeal Mask (ILMA) has a curveduohy style tip, allowing the leading edge o the tube to run closeralong the scope when it is pushed over it. Tis reduces the likelihoodthat the tube will get caught at the arytenoids or vocal cords (Figure5).


Figure 4. Looking to the let is achieved by elevating the tip (i.e. leverdown, tip up) and rotating the scope 90 anticlockwise or by depressing

the tip (i.e. lever up, tip down) and rotating 90 clockwise

Figure 5. Diferent prole o an armoured ETT (on the let) with a

prominent lip, as indicated by the arrow and an ILMA tube (on the right)

North acing Portex nasal tubes, (typically size 6 or emales and6.5 or males) are oten used or maxillo-acial procedures. Tesetubes are made o sot material. Te catheter mount connection ispositionedawayfromthesurgicaleld,therebyimprovingsurgicalaccess.

Figure 6. Portex north-acing nasal tube

PREPARATION OF THE PATIENT

General aspectsAppropriate preparation o the patient is a key actor in achievinga calm and controlled environment to perorm a successul awake


4/8page 30 Update in Anaesthesia | www.anaesthesiologists.org

intubation. Te procedure should be explained and consentobtained. Explain to the patient that sedation is not anaesthesia andsome degree o recall or events is possible. Tey may have undergonethe procedure beore so it is important to know whether this was a

good or bad experience.

Full monitoring should be applied beore starting the procedure.

An anti-sialogogue is generally recommended to reduce secretionsthatmayobscurethebreopticview.Drymucousmembranesmayalso allow the topicalisation with local anaesthetic to work moreeectively. Glycopyrronium is usually used and it can be givensubcutaneously or intramuscularly an hour beore the intubation.

Alternatively it can be given intravenously when the patient arrivesin the anaesthetic room. Te standard dose is 4mcg.kg-1 or allroutes. Atropine (20mcg.kg-1 to a maximum o 500mcg) is a suitablealternative.

Patient and operator position (Figure 7)

Te patient can be positioned sitting up, with the operator acingthe patient, or lying supine with the operator standing behind thepatient at the head o the trolley. Te choice is usually inuenced byprior experience - many anaesthetists will be more comortable atthe head o the bed, whereas most physician bronchoscopists standacing the patient. I you use an unamiliar position the image yousee will be inverted.

OXYGEN DELIVERY

Oxygenation during the procedure is important, especially iadministering sedation. It may be slightly awkward to adequatelyoxygenate the patient while maintaining access or instrumentationo the nose or mouth. Helpul devices include single nasal prongs, anasal sponge (Figure 8) or a Hudson acemask cut appropriately toallow access to the nostril o the patient.

Figure 7. Intubation with the operator standing behind the patient (A) and in ront o the patient (B)

Table 3. Benets o the sitting and supine position

Benefts o sitting position Benefts o supine position

(Operator in ront) (Operator behind)

Eyecontactbetweenpatientandoperator Familiaritywithposition

Lesspoolingofsecretions Goodlineofaccess

Morecomfortableforoperator(i.e.lesstiringonoperatingarm) Betterforpatientsunabletositupe.g.cervical spineinjury

Figure 8. Nasal sponge

SEDATION

Sedative drugs and techniques

Provided that saety is not compromised, conscious sedation isdesirable to minimise awareness o the procedure. Remember that

A B

Morecomfortableforpatient

Airwaymoreopen/patent Betterpatientventilatione.g.COPD


5/8

good local anaesthesia is the essential ingredient in this techniqueand avoidance o sedation may be the saest option in some settingsor some patients. Te goal is to provide analgesia and amnesia in acalm and cooperative patient who can ollow verbal commands while

maintaining a patent airway, adequate oxygenation and ventilation.Somedegreeofairwayreexandcoughsuppressionisalsobenecial.

Tere are a variety o sedation techniques used by anaesthetists andchoice is largely determined by availability. Tere is no single idealagent. Fentanyl and alentanil are commonly used. An inusion oremientanil has become popular in UK due to its advantageouspharmacokineticprole.Ithasaconstantcontextsensitivehalf-time,

which means that it does not accumulate and once the inusion stopsthe analgesic and sedative eect wears o quickly. Sedation withketamine2 has been described, either used alone or in conjunction

with other drugs.

Remientanil provides good conditions or the patient and operatorwith its analgesic, antitussive and sedative properties. Tis, combinedwith its short duration o action allows appropriate titration tothe stimulation associated with airway manipulation. Caution is

required when using this drug as apnoeas are not always obvious andcan occur when the patient appears to be awake. Capnography anda gentle reminder to breathe can help to avert this situation.

A recent study demonstrated similar satisaction scores by patientswhen comparing remientanil to propool despite a higher level orecall when using remientanil.3

Te table below illustrates some o the possible drug regimens whichcan be used or sedation. Approximate dose ranges are included,but the actual dose required may vary depending upon the age andphysiological status o the patient. All drugs should be administeredcautiously and titrated to eect.

Table 4. Suggested dosing regimens or some sedative drugs

Drug Dosage

Propool Target controlled inusion: Start with a target o 0.75-1.5mcg.ml-1andadjustby0.25-0.5mcg.ml-1

Simple inusion:Startwitha1%propofolsolutionrunningat10ml.h-1 and titrate up to 30ml.h-1 as needed

Remientanil Target controlled inusion: Start at 1.5-2ng.ml-1andadjustby0.25-0.5ng.ml-1.

Simple inusion (mcg.kg-1.min-1): Start at 0.05-0.1mcg.kg-1.min-1 and titrate accordingly (0.025-0.05 increments)alternatively inuse 5-10ml.h-1 o a 50mcg.ml-1 solution.

Remember that it may take over 5 minutes or the steady state o remientanil to be reached.

Midazolam Intermittent intravenous bolus: Dilute 10mg of midazolam to a total volume of 10ml 0.9% sodium chloride(1mg.ml-1) and administering 0.5-1mg intravenously as boluses.

Diazepamisanalternative.

Morphine Intermittent intravenous bolus: 0.5-1mg bolus

Fentanyl Intermittent intravenous bolus: 20-40mcg bolus

Ketamine Intermittent intravenous bolus: 0.25-0.5mg.kg-1 bolus

Remientanil

Advantages Disadvantages

Short-acting Respiratory depression

Constantcontextsensitive Lesseectiveanxiolysishal-time

Propool

Advantages Disadvantages

Short-acting Respiratory depression

Rapid clearance Haemodynamic instability

Doserelatedsedationtime Variablecontextsensitivehalf

Dose related amnesia

Nondoserelatedanxiolysis

Table 5.Advantages and disadvantages o remientanil and propool sedation


No analgesic properties

Rapid clearance

Haemodynamic instability(high doses)

Muscle rigidity (high doses)

Nausea and pruritus

Less eective amnesia

Antitussive

Analgesic

Sedative


6/8

LOCAL ANAESTHESIA OF THE AIRWAY

Once sedation has begun, a vasoconstrictor applied nasally willdecrease localised blood ow (thus reducing the risk o epistaxis)and prolong the eect o the local anaesthetic (by reducing the rateo absorption). ypical vasoconstrictors are epinephrine (0.1%),ephedrine (0.5%), phenylephrine (0.5%-1%) and xylometazoline(0.05%). 1-2 drops in each nostril should achieve vasoconstriction.Be cautious in patients with pre-existing medical conditions suchas hypertension. A combination o vasoconstrictor plus localanaesthetic can be used e.g. Co-Phenylcaine (50mg.ml -1 lidocaine,5mg.ml-1 phenylephrine).

ere are many ways to anaesthetise the airway for breopticintubation. We describe our avoured technique (able 6), but havealso mentioned alternative techniques. Te exact choice o techniqueor combination o techniques is dictated by local availability o drugs

and administration devices and by personal choice and experience.In patients with distorted airway anatomy or riable tumours, invasivenerve blocks should be avoided. Lidocaine may be used in a varietyofconcentrations;themaximumsafetopicaldoseforairwaymucosahas been shown to be up to 9mg.kg-1.6

Anaesthetising the nasopharynx

etrigeminalnerveprovidesthesensorybrestothenasalmucosavia the sphenopalatine ganglion, which also innervates the superiorsegments o the tonsils, uvula and pharynx. Tere are dierenttechniques to anaesthetise the nose. Our choice is Co-Phenylcaineollowed by Instillagel (2% lignocaine and chlorhexidine) to thenares.

Lidocaine can sting when applied to mucosal suraces. However, itopicalisation is commenced at a low concentration and increasedto a stronger concentration, it tends to be better tolerated by thepatient. Warming the local anaesthetic to body temperature may alsoreduce the stinging associated with topicalisation.5 Also, althoughtopicalisation is applied predominantly into the chosen nostril, asmall amount should be applied to the other nostril since there isoten some cross-innervation o the nasal septum.

Other alternative methods include:

4%cocainesoakedcottonswabs

nebulised4%lidocaine(4-6mls)

Moets solutionwhichis 1ml 1:1000 epinephrine, 2ml 1%sodium bicarbonate and 2ml 10% cocaine.

Anaesthetising the oropharynx

Te pharynx and posterior third o the tongue are innervated by theglossopharyngeal nerve.

Mucosalatomiserdevices(MAD)areusefultoassistindepositing

thelocalanaestheticasnedroplets.ereareseveraldierenttypes o this device available commercially. However a similareect can be achieved by attaching a 20G cannula to some greenoxygen tubing via a three-way tap. Te local anaesthetic can thenbe injected via the cannula port, and an oxygen ow rate o4-8l.min-1 produces good atomisation (Figure 9). Reassure thepatient that coughing may occur during this time.

Table 6. Easy steps to anaesthetise the airway

Nasopharynx Co-PhenylcainesniedupbothnostrilsandInstillagel to both nares

Oropharynx MucosalAtomisingDevice(MAD)(purpose designedorimprovised-seetext):10ml1%

lignocaine

Larynx Spray-as-you-go4%lignocaine(2mlx3)down sideportofthescope,abovethelarynxandonto

the vocal cords (where available using an epiduralcatheter)

Fullyoperationalscope/TVmonitorsetupandchecked

Monitoringequipment/Resuscitationfacilities,Skilledassistant

Suction apparatus

Oxygensupply:facemask/nasalsponge,greentubing

Dierenttypes/sizeETTs(6.0,6.5exiblereinforcedETTs)

Split oral airway (Berman or Ovassapian)

IVcannula,glycopyrrolate4mcg.kg-1

Co-phenylcaine 2.5mls (to nostril)

Laryngo-Tracheal Mucosal Atomisation Device

Epiduralcatheter16G(withtipcuto)/openendedcatheter

2%lidocainegel(Instillagel)5mltomouthtogargle

1%lidocaine10mlviaMADoverbackoftonguedirectedtolarynx

4%lidocaine2mlx3(in5mlsyringewith2mlair)

Warm sterile saline (to soten tube), KY Jelly (nose)

Saline (lubrication or railroading tube over scope)Figure 9. Improvised Mucosal Atomiser Device (MAD)

page 32 Update in Anaesthesia | www.anaesthesiologists.org

Box 1. Summary checklist o equipment required or awake breopticintubation


7/8

A benzocaine lozenge may be used to start the process ofanaesthesia.

Instillagel can be gargled orally to anaesthetise the pharynx,ollowed by 1% and 4% lidocaine spray.

Anaesthetising the larynx

enalnervetobeanaesthetisedisthevagus.isnervesuppliessensory branches both above and below the vocal cords via twomain branches. Te superior laryngeal nerve supplies the arytenoids,epiglottis and sensation above the cords. Below the cords, the sensoryinnervation is supplied via the recurrent laryngeal nerve.

Te commonest method to anaesthetise the larynx is to spraylignocainedirectlydownthebrescopesideport(spray-as-you-gotechnique).

Spray-as-you-go technique

isisatechniquewherethelarynxisidentiedusingthebrescopeand anaesthetised as visualised.6 A simple method is to inject thelocal anaesthetic directly down the side port.

However or a more accurate administration o local anaestheticonto and below the cords an epidural catheter is useul. Teepidural catheter is threaded out o the end o the scope and 2ml4% lidocaine is injected onto the cords (Figure 10). Tis can eitherbe trickled onto the cords, or a more orceul jet can be achievedby the addition o air into the injecting syringe (with the syringeheld vertically pointing downwards). Both techniques will cause thepatient to cough and the view o the cords may be temporarily lost, so

itisimportanttoremainpatientandkeepthebrescopeinthesameposition until the view clears. Make sure that the epidural catheteris retracted ater injecting, to avoid airway irritation or scratching bythe tip.

therewerenosignicantdierencesinsystolicbloodpressureorpulseat various stages o airway manipulation.7 Both produced clinicallyacceptable intubating conditions for awake breoptic intubation.However the total doses and subsequent plasma concentrations

were less in the patients who received the 2% dose. Tis has useulimplications or clinical practice rom a saety aspect, and in countries

where there is no access to 4% lidocaine it is useul to know thatlower concentrations can work equally well.

Other techniques include:

Regional nerve blocks

Although regional nerve blocks are requently described, they arecomplicated and invasive to perorm, and thereore rarely done and

will not be discussed urther.

Nebulisation o lignocaine

Nebulised 4% lignocaine can also be used as the initial anaestheticor the airway. One suggested regimen is 5ml over 10-15 minutes.Tis technique is efcient but may be more time-consuming.

Translaryngeal block

Also known as cricothyroid puncture, this is another method oranaesthetising the larynx. A 20G cannula is inserted through thecricothyroid membrane and ater air has been aspirated, 2-3ml2% or 4% lidocaine is injected, asking the patient to breathe outully prior to injection. Te subsequent inspiration and coughingwilldisperse thelocalanaesthetic eciently.ebenetof usingacannula compared to a needle is that there is reduced risk o trauma

during the procedure. ranstracheal injection is a very useul way otopicalisingthelarynxandtracheaifyoudonothaveabrescopetodirect the local anaesthetic and can produce excellent conditions. Itis also very useul i there is an obstructed view o the larynx romabove (e.g. by glottic or supraglottic tumour).

Patients who have undergone any o these procedures or airwayanaesthesia remain at risk o aspiration into the airway or severalhours ater the procedure.

BRONCHOSCOPY AND INTUBATION

Te operator passes the scope under direct vision through the noseor mouth and into the pharynx. At all times the scope should be heldtaught and straight. Small movements o the tip o the scope tend toallow the most successul manoeuvring through the airway.

Difculty may sometimes be caused when patients have a smallpharyngeal cavity, due to normal variation in anatomy, recedingmandible, or disease causing swelling or oedema. Asking the patientto sni can enlarge the nasopharyngeal cavity. Asking the patientto stick out their tongue or jaw can improve the view in the lowerpharyngealspace.Secretionsandmistingofthebreopticlensmayalso obscure the view on the end o the scope. Careully brushing theadjacent mucous membranes with the tip can oten clear the view orasking the patient to swallow.

I you get lost or lose the airspace, i.e. your scope is sittingin secretions (white-out), or lying against a mucosal surace(pink -out), then withdraw slightly until your view is re-established.

Figure 10. Transendoscopic local anaesthetic administration through an

epidural catheter

ebrescopecanbeadvancedclosertothecordsandtheepiduralcatheter can oten be placed through the cords allowing a urther doseo 2ml 4% lidocaine to be injected below the cords. Again coughingis to be expected and the epidural catheter should be withdrawn until

the patient settles.A recent randomised, double-blind comparison o 2% and 4%lidocaine or topical spray-as-you-go anaesthesia demonstrated that



8/8

Once the epiglottis and cords are visualised (Figure 11) the spray-as-you-go technique can be instigated i this is your technique o choice.Te eect o the topical anaesthesia on the cords can be assessedby observing the reactivity o the larynx to the lidocaine spray. An

absent or markedly subdued cough usually indicates an adequatelyanaesthetised larynx.

Asking the patient to take a deep breath oten acilitates entry o thescope through the vocal cords. Once through the cords, careullyadvance the tip o the scope a reasonable distance beyond the cords,beforerailroadingtheETToverthebrescope.Asmallamountofsaline administered into the E at this point can reduce rictionbetween the scope and the tube. Lubrication (i.e. KY Jelly) shouldalso be applied to the nares and/or the cu o the E, beore it isinserted into the nostril (or mouth) and railroaded over the scope.Passing the endotracheal tube through the nostril is one o thepotentially more stimulating parts o the procedure or the patientand some reassurance is oten required at this point.

Loosentheendotrachealtubeconnectorfromthebrescopehandle.A gentle twisting motion should allow the tube to pass without toomuch orce. I resistance is met, it is likely that the tube tip has caughton the arytenoids. A 360 continual rotation or drilling o the tubeshould overcome any hold-up when using a reinorced tube. Withthe blue Portex pre-ormed tube, a 90-180 anticlockwise rotation(o both the tube and the scope and advancing both together) canusually overcome the hold-up and allow the tube to advance past thearytenoids and through the cords.

Figure 11. View o the larynx

Advance the endotracheal tube into the trachea over the scopeuntil the tip o the tube is correctly positioned above the carina.Withdrawthebrescopeandattachthe circuitto theendotrachealtube.Capnographywillalsoconrmcorrectplacementandgeneralanaesthesia can now be induced. Tis can be done intravenously oras an inhalational induction. Te endotracheal tube cu should notbe inated until ater induction o anaesthesia.

COMPLICATIONS

Operator skill and practice will help to ensure a straightorwardand successul intubation. Bleeding rom minor trauma can make

a potentially difcult airway unnecessarily more complicated. Apatient who is coughing may end up with more upper airwaybruising than one whose airway reexes are quiescent. I protracted

coughing occurs it may indicate inadequate anaesthesia or sedation.Both can be adjusted accordingly. echnical ailure can be minimisedby ensuring all equipment is checked prior to proceeding and theanaesthetist should always be vigilant to the possibility o airway

obstruction that may be exacerbated by sedation. Equally a degree oobstruction may occur once the scope enters the larynx or trachea.Remember that an awake tracheostomy may be the most appropriateline o management in patients with extremely critical airways.

Awakebreoptic intubation is a procedure inwhich fairly liberalamounts o local anaesthetic may be used (especially i sedationis contraindicated) and this is not without risk. Te anaesthetistshould be vigilant in monitoring or signs o toxicity and overdose,remembering that peak absorption o topical anaesthesia can occur15-60 minutes ollowing administration.

Table 7. Complications o awake breoptic intubation

Equipmentfailure Poorview/fogging

Bleeding/haematoma Coughing

Complete airway obstruction Oesophageal intubation

Localanaesthetictoxicity FailuretopassETT(intubate)

SUMMARY

Awakebreopticintubationperformedbyaskilledoperator allowsthe airway to be secured saely in situations where conventionallaryngoscopy may prove challenging. It is a straightorward techniquethat, once mastered, is an extremely valuable skill. Te key to its

success is thorough preparation o the equipment and the patient.Since there is a variety o ways to provide sedation and airwayanaesthesia, each individual anaesthetist will adopt a practice withwhichtheyfeelcondentandtailorittoeachpatientsrequirements.Although it is imperative to have an understanding o the principlesunderlying awake breoptic intubation, nothing can replace theexperience gained by directly observing and practising the technique.

REFERENCES

1. OvassapianA, KrejciesTC,Yelich J, etal.Awakebreoptic intubationin

the patient at high risk o aspiration. Br J Anaesth 1989; 62: 13-16.

2. Popat MT. Practical Fibreoptic Intubation. Butterworth-Heinemann.Published 2001.

3. Rai MR, Parry TM, Dombrovskis A et al. Remientanil target-controlledinusion vs. propool target-controlled inusion or conscious sedation

for awake breoptic intubation: a double-blinded randomized

controlled trial. Br J Anaesth 2008; 100: 125-30.

4. Marsland CP, Martin KM, Larsen PD, Segal R; Lidocaine toxicity in volunteer subjects undergoing awake breoptic intubation. Anesth

Analg 2005; 101: 607.

5. Bell RW & Butt ZA;Warming lignocaine reduces the pain of injection

during peribulbar local anaesthesia or cataract surgery. Br JOphthalmol1995; 79: 1015-7.

6. Williams KA, Barker GL, Harwood RJ et al. Combined nebulisation andspray-as-you-go topical local anaesthesia o the airway. Br J Anaesth2005; 95: 549-53.

7. Xue F, Liu H,He N,et al. Spray-as-you-goairway topical anaesthesiainpatients with a dicult airway: a randomised, double-blind comparison of 2% and 4% lidocaine. Anesth Analg 2009; 108: 536-

43.

page 34 Update in Anaesthesia | www.anaesthesiologists.org

Documents

Fibreoptic_intubation_Update_2011.pdf