PDF (523 KB)

14 Pages·2011·0.49 MB·English

BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276
ContentslistsavailableatScienceDirect
Best Practice & Research Clinical
Anaesthesiology
journal homepage: www.elsevier.com/locate/bean
14
Closed claims’ analysis
Julia Metzner, MD, Assistant Professora, Karen L. Posner, PhD, Research
Professorb, Michelle S. Lam, BS, Research Study Assistantc, Karen B. Domino,
MD, MPH, Professor*
DepartmentofAnesthesiology&PainMedicine,Box356540,UniversityofWashington,Seattle,WA98195-6540,USA
The American Society of Anesthesiologists (ASA) Closed Claims
Keywords:
database was started in 1985 to study anaesthesia injuries to
outcomes
outcomesresearch improve patient safety, now containing 8954 claims with 5230
regionalanaesthesia claimssince1990.Overthedecades,claimsforsurgicalanaesthesia
airwaymanagement decreased, while claims foracuteand chronic pain management
obstetricanaesthesia increased.Inthe2000s,chronicpainmanagementinvolved18%,
medicationtherapymanagement acutepainmanagement9%andobstetricalanaesthesiaformed8%of
claimsanalysis
claims.Surgicalanaesthesiaclaimswithmonitoredanaesthesiacare
perioperativecomplications
(MAC) increased in the 2000s to 10% of claims, while regional
burns
anaesthesiainvolved19%.Themostcommoncomplicationswere
death(26%),nerveinjury(22%)andpermanentbraindamage(9%).
Themostcommondamagingeventsduetoanaesthesiainclaims
wereregional-block-related(20%),respiratory(17%),cardiovascular
(13%)andequipment-relatedevents(10%).Thisreviewexamines
recentfindingsandclinicalimplicationsforinjuriesinmanagement
ofthedifficultairway,MAC,non-operatingroomlocations,obstetric
anaesthesiaandchronicpainmanagement.
(cid:1)2011ElsevierLtd.Allrightsreserved.
Background
Inresponsetorapidlyrisingprofessionalliabilityinsurancepremiumsduringtheearly1980s,the
AmericanSocietyofAnesthesiologists(ASA)ClosedClaimsProjectwasestablishedin1984toimprove
patient safety and prevent anaesthetic injury.1 At that time, anaesthesiologists were regarded as
* Correspondingauthor.Tel.:þ12066162627;Fax:þ12065432958.
E-mailaddresses:[email protected](J.Metzner),[email protected](K.L.Posner),[email protected].
edu(M.S.Lam),[email protected](K.B.Domino).
a Tel.:þ12065987985;Fax:þ12065984544.
b Tel.:þ12066162630;Fax:þ12065432958.
c Tel.:þ12066166457;Fax:þ12065432958.
1521-6896/$–seefrontmatter(cid:1)2011ElsevierLtd.Allrightsreserved.
doi:10.1016/j.bpa.2011.02.007
264 J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276
especially poor malpractice insurance risks, as 11% of total dollars paid for patient injury were
anaesthetic-relatedcomplicationsdespiteanaesthesiologistsaccountingforonly3%oftotalphysicians
insured.TheASAClosedClaimsProjectaimedtoidentifymajorareasoflossinanaesthesiaandanalyse
patternsofinjurytodevisestrategiesforprevention,therebyreducingpatientinjuriesandassociated
malpracticeclaimsandconsequentpayments,andleadingtoadecreaseinpremiums.
Created to provide a systematic and structured evaluation of adverse anaesthetic outcomes, the
ClosedClaimsProjectreviewsandanalysesclosedclaimsfilesofUnitedStates professionalliability
insurancecompanies.Theinsurancecompaniesparticipatingintheprojectincludestate-wideorga-
nisationsthatcomprisebothphysician-ownedandprivatecompanies,aswellascompaniesinsuring
anaesthesiologistsinmultiplestates.
Thedatacollectionprocesshasbeenpreviouslydescribedindetail.1,2Briefly,theclosedclaimfiles
typicallyconsistofthehospitalandmedicalrecords,narrativestatementsfrominvolvedhealth-care
personnel,expertandpeerreviews,depositionsummaries,outcomereportsandthecostofsettlement
or jury awards. Dental injury claims are excluded from the database, as are claims in which the
sequence of events and nature of the injury cannot be reconstructed from the insurance company
records. As a consequence, most (but not all) data are derived from lawsuits. Data are collected
regardlessofthelitigationoutcome;claimsbothwithandwithoutpaymentareincludedintheproject.
Claimsdataarecollectedbyoneormoretrainedpracticinganaesthesiologists,whovisiteachinsur-
ancecompanyofficeatperiodicintervalstoreviewclaimsfiledagainstfellowprofessionals.Anaes-
thesiologistclaimsreviewerscompleteastandardisedformforeachclaimwithinformationonpatient
characteristics, surgical procedures, sequence and location of events, critical incidents and injuries,
severityofinjury,standardofcare,outcomeandpayments.Adetailedsummaryofthesequenceof
medical events is included. The current ASA Closed Claims Project database contains 8954 claims
representingeventsthatoccurredfrom1970through2007,with5230claimssince1990.
Strengthsandlimitationsofclosedclaimsanalysis
Closedclaimsdataanalysishasdistinctstrengthsandlimitationsthatdifferfromother‘outcomes’
research.Oneofthestrengthsistheabilitytostudyalargecollectionofrelativelyrareevents.Studying
insurancecompanyclosedclaimfilesisacost-effectiveapproachtosuchresearch,asthesefilescontain
extensive data on injuries that occurred at many different institutions and have been gathered in
a centralised location. Closed claims data can be analysed as a large collection of ‘sentinel events’
revealingrelativelyrare,yetimportant,sourcesofpatientinjury.Forexample,theASAClosedClaims
Project database contains detailed clinical information on large collections of difficult intubations,
pulmonaryaspirations,centralvenouscathetercomplications,medicationerrorsandotherrelatively
uncommoncomplications(Table1)thatwouldbedifficultandcostlytoobtainfromstandardmedical
recordormulti-institutionalclinicalinvestigations.
Althoughtheuseofclosedclaimsrepresentsacost-effectivemethodofstudyingrareanaesthetic
complications, this approach includes inherent limitations that have been previously described.1–3
The incidence and risk of anaesthetic-related adverse outcomes are unknown due to the absence
ofnumeratordata regarding thetotalnumberofadverse events anddenominatordataforthe total
number of anaesthetic procedures performed. Professional liability insurance companies that insure
Table1
“SentinelEvents”associatedwithanaesthesia.
No.Claims
Permanentbraindamage 867
Airwayinjury 581
Difficultintubation 466
Spinalcordinjury 417
Medicationerrors 283
Aspiration 213
Centralvenouscatheterinjury 183
ASAClosedClaimsN¼8954.
J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276 265
approximatelyone-thirdofallpracticinganaesthesiologistsintheUnitedStatesparticipateintheClosed
ClaimsProject.ThesecompaniesarelocatedpredominantlyintheNortheast,Southeast,upperMidwest
andWestCoast;hence,geographicvariationsinanaesthesiapracticemayinfluencethefrequencyand
typeofadverseeventsfoundintheClosedClaimsdatabase.Inaddition,malpracticeclaimsrepresentonly
asmallsubsetofadverseoutcomes,assomeinjuredpatientsdonotfileclaims,whereasothersfileclaims
withoutanyapparentinjury.4,5Professionalliabilitycompaniesalsodonotmaintainrecordsonthetotal
numberofanaestheticsadministeredbyinsuredphysicians.TheClosedClaimsdatabasedoesnotoffer
anycontrolgroupsforcomparison.Anotherlimitationoftheclaimsisthattheyarebiasedtowardsmore
severeandcostlyinjuries,whichmayresultinhigherfinancialcompensationandahigherproportionof
deaths. Furthermore, ambiguities in the judgement of the appropriateness of care also exist among
reviewers,resultinginpoorinter-raterreliability6andoutcomebias.7Finally,theretrospective,non-
randomisedcollectionofdatafromparticipatinginsurersmaycontainconflictingormissingaccountsof
theadverseeventfromdifferentsources,andthuscannotbeusedtotesthypothesesorestablishcause-
and-effectrelationshipsofpreviousevents.Nevertheless,analysisoflargenumbersofadverseeventscan
revealpatternsofinjuryandidentifyriskfactorsthatshouldbeaddressedtoimprovepatientsafety.1
Recenttrendsandfindingsinclosedclaims
Trendsinanaesthesiamalpracticeclaims
Early anaesthesia claims collected by the ASA Closed Claims Project reflected mainly surgical
anaesthesiacare.Thispatternhaschangedconsiderablyoverthedecades.Inthe1980s,forexample,
surgicalanaesthesiarepresentedmorethan80%ofallclaims,whileclaimsassociatedwithacuteand
chronic pain care were relatively rare. This profile of claims changed in the 1990s, with surgical
anaesthesia claims declining to 72% of all claims and chronic pain (11%) becoming as common as
obstetric anaesthesia claims (12%, Fig. 1). Chronic pain management has continued to increase as
asourceofclaims,representing18%ofallclaimsfrom2000to2007(Fig.1).Acutepainalsoincreased,
representing9%ofclaimssince2000,similartoobstetricanaesthesiaclaimsat8%ofclaimssince2000.
Bycontrast,surgicalanaesthesiadeclinedto65%ofanaesthesiamalpracticeclaimssince2000.
Mostcommoncomplications:1990–2007
Complications leading to anaesthesia malpractice claims have changed considerably since the
1970s.Withintroductionofmodernrespiratorymonitoringinthemid-1980s,andadoptionofnew
20%
Obstetric Anesthesia
d *
o Chronic Pain
ri
e
p Acute Pain
e 15%
m
n ti *
s i
m 10% *
ai *
cl
al *
ot 5%
of t
%
0%
1980s 1990s 2000s
n=2965 n=3821 n=1396
Fig.1. Proportionofobstetric,chronicpain,andacutepainclaimsbydecade.Claimsforsurgicalanaesthesianotshown.*p<0.01
comparedto1980sbyztest.
266 J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276
standardsofcareforpatientmonitoringaswellaspracticeguidelinesformanagementofthedifficult
airwayin1993,8deathandbraindamagehavedeclinedsignificantly.9Alookattheinjuryprofilein
claimsforeventssince1990reflectscurrentanaesthesiamalpracticeinjurytrendsintheU.S.
Deathwasstilltheleadingoutcomeinanaesthesiaclaimsin1990–2007(Fig.2).Permanentbrain
damagerepresented9%ofclaims,whilenerveinjuryaccountedfor22%ofclaims.Whilemostnerve
injuryclaimsweretemporaryornon-disablinginjuries,23%werepermanentanddisabling,including
lossoflimbfunction,orparaplegiaorquadriplegia.Thefourthmostcommoninjuryinclaimswasairway
injury,accountingfor7%ofclaims(Fig.2).Theremainderofinjuriesinclaimseachaccountedfor5%or
fewerclaimsinthedatabase.Emotionaldistresswasfairlycommon,citedin5%ofclaims.Eyeinjuries
includingblindnessfromopticnervedamage,globeperforationduringblocksorretinalhaemorrhage
accounted for 4% of claims. Other complications included pneumothorax from peripheral blocks,
headacheorbackpainusuallyassociatedwithlabourepidurals,newborninjury,strokeandmyocardial
infarction.Awarenessduringgeneralanaesthesiawascitedinonly2%ofclaimsin1990–2007.
Trendsinanaesthesiatechniqueandassociatedcomplications
WhiletheASAClosedClaimsProjectdatabaselacksadenominatorofthetotalanaestheticsfrom
whichtheclaimsarose,trendsinmalpracticeclaimsdataappeartocorrespondtotrendsinanaesthesia
practice.Forexample,justasclaimsforchronicandacuteclaimmanagementhaveincreasedfromthe
1980s to the 1990s and 2000s, claims for monitored anaesthesia care (MAC) have also shown an
increaseoverthedecades(Fig.3).MACwastheprimaryanaesthetictechniqueinonly2%ofclaimsfor
injuriesinthe1980s,increasingto5%inthe1990sandtoafull10%ofclaimsin2000andlater(Fig.3).
Regionalanaesthesiahascontinuedtorepresentnearly20–25%ofclaimsineachdecade.
Ananalysisofsurgicalanaesthesiaclaimsforeventsfrom1990to2007showsaprofileofinjuries
related to MAC that is distinct from general and regional anaesthesia claims. Death was the most
common outcome in claims associated with MAC, representing 38% of surgical anaesthesia claims
associatedwithMACin1990–2007(Fig.4).Deathwassignificantlymorecommoninclaimsassociated
withMACthaninclaimsassociatedwithgeneralanaesthesiaorregionalanaesthesiaduringthistime
period(Fig.4).Permanentbraindamagerepresented8–10%ofsurgicalanaesthesiaclaimsregardlessof
primary anaesthetic technique. Permanent nerve injury, on the other hand, was more commonly
associatedwithregionalanaesthesia(15%)andgeneralanaesthesia(5%,Fig.4).
Mostcommondamagingeventsleadingtoanaesthesiaclaims1990–2007
Analysisofthemostcommoninjuriesinclaimsmayhelpfocuspatientsafetyeffortsonthemost
commonandsevereinjuries.However,analysisoftheeventsthatleadtotheseinjuriesiscriticalin
identifyingcausesofcomplicationsandsuggestingpreventivestrategies.
Fig.2. Mostcommoncomplications1990orlater(n¼5230).
J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276 267
80% General
od Regional ** **
eri MAC
p
e 60%
m
ti
n
s i
m 40%
ai
otal cl 20% ** *
of t **
% **
0%
1980s 1990s 2000s
n=2759 n=3199 n=1049
Fig.3. Proportionofgeneral,regionalandMACclaimsbydecade.MAC¼monitoredanaesthesiacare.Claimsforchronicpain
management(n¼1697)excluded.Claimswithnoanaestheticorcombinedgeneralanaestheticþregionalanaestheticexcluded.
*p<0.05comparedto1980s;**p<0.01comparedto1980s.
The most common events leading to injury in anaesthesia claims were regional-block-related,
accountingfor20%ofclaimsin1990–2007(Fig.5).Respiratorysystemmanagementissuesaccounted
for17%ofclaimsandcardiovasculareventsfor13%ofclaims.Theinjurywasattributedtothesurgical
procedureorpatientconditionin11%ofclaims,andtoequipmentproblemsin10%ofclaims.Other
anaestheticeventswerethesourceof9%ofclaims,andmedicationissueswererelatedto8%ofclaims
in this time period. In another 10% of claims, no event occurred. Claims with no event are most
commonly nerve injuries in which no anaesthesia management factors leading to injury could be
identified.Thefollowingsectionwillfocusfurtheronthespecificmechanismsofinjuryinanaesthesia
claims(e.g.,surgical,obstetricandacutepainclaims),excludingthoseforchronicpainmanagement,as
thetreatmentmodalitiesandinjurycausationdiffersubstantiallyfromanaesthesiaclaims.
Specificdamagingeventsinanaesthesiainjury
Themostcommonrespiratorysystemeventsleadingtoanaesthesiaclaimssince1990weredifficult
intubation,inadequateoxygenationorventilation,andpulmonaryaspiration(Table2).
Fig.4. Injuriesbytypeofanaesthesiainsurgicalclaims1990orlater.Acutepain,chronicpainandobstetricanaesthesiaclaims
excluded.Claimswithnoanaestheticorgeneralanaestheticþregionalanaestheticexcluded.*p<0.05comparedtoMAC;**p<0.01
comparedtoMAC.
268 J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276
Fig.5. Mostcommondamagingevents1990orlater(n¼5230).
Sincethe1970stothe1980s,oesophagealintubationhasnearlydisappearedwithadoptionofend-
tidalcapnography(Fig.6).10Inadequateoxygenationorventilationhasalsodeclinedwiththeadoption
of pulse oximetry as a standard of intra-operative monitoring (Fig. 6).9 However, inadequate
oxygenation/ventilationhasmorerecentlyarisenasaproblemduringMACandnon-operatingroom
locations, often associated with oversedation and inadequate monitoring of ventilation,11,12 as
described later in this article. Difficult intubation remains a concern, representing 27% of adverse
respiratoryevents in1990–2007(Fig.6).Pulmonaryaspirationofgastriccontents isthethirdmost
commonrespiratoryeventleadingtoanaesthesiamalpracticeclaimsin1990–2007(Fig.6).
Regional-block-managementproblemsoccurredin15%ofanaesthesiaclaimsin1990–2007(Table2).
Most regional-block-management claims were associated with surgical anaesthesia care (45%), but
a significant number were associated with obstetric anaesthesia (37%) and acute pain management
(18%).Most(74%)eventsassociatedwithregional-blocktechniqueinvolvedneuraxialblocks.Theother
regional-block-related claims were associated with peripheral nerve blocks (15%, most commonly
interscaleneandaxillarytechniques)andeyeblocks(8%).Therewerenospecificeventsthatemergedas
prominentinthecauseofblock-relatedclaims,andnerveinjurywasthemostcommonoutcome(57%of
block-related claims). Death occurred in 9% of regional-block-related claims and permanent brain
damagein9%.Injuriesassociatedwithregionalblockshavebeenrecentlyreviewedindetail.13,14
Cardiovasculareventswereobservedtoincreaseasacauseofdeathandbraindamageinclosed
claims.9Cardiovasculareventswereassociatedwith15%ofallanaesthesiaclaimsin1990–2007.The
mostcommonspecificcardiovasculareventsintheseclaimswerehaemorrhageorbloodreplacement
(3%),electrolyteimbalanceorfluidmanagement(2%)andstroke(2%).In3%ofclaims,acardiovascular
event was evident, but could not be more specificallycharacterised. Most cardiovascular damaging
eventsresultedindeath(64%)orpermanentbraindamage(21%).
Equipmentproblemswerenotablefortheroleofcentralandperipheralvenouscathetersinclaims.
While earlyclosed claims analysisidentified anaesthesia-gas-deliverysystems (gas supplies, anaes-
thesiamachines,ventilatorsandbreathingcircuits)asasourceofpatientinjury,15theseproblemsnow
accountforonly1%ofclaims.Centralvenouscathetersaccountedfor3%ofclaimsin1990–2007,while
peripheral catheters accounted for 2% of all claims. Central venous catheter claims had a high
proportion of deaths, and problems were most commonly associated with access rather than use
ofcatheters.16Themostcommoncomplicationsassociatedwithcentralvenouscatheterswerewire/
catheter embolus, cardiac tamponade, carotid artery puncture/cannulation, haemothorax and
J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276 269
Table2
Mostcommondamagingeventsinanaesthesiaclaims1990orlater.
%of4549
RespiratoryEvents(n¼865)
Difficultintubation 5%
Inadequateoxygenation/ventilation 4%
Aspiration 3%
Prematureextubation 2%
Airwayobstruction 2%
RegionalBlock(n¼681)
Duralpuncture 1%
Highblock 1%
Unexplainedblockcomplication 1%
Neuraxialcardiacarrest 1%
Inadequateanalgesiafromblock 1%
Blockneedletrauma 1%
Retainedcatheter 1%
CardiovascularEvents(n¼665)
Unexplainedcardiovascularevent 3%
Hemorrhage/bloodreplacement 3%
Electrolyteimbalance/fluidmanagement 2%
Stroke 2%
Equipment(n¼506)
Centralvenouscatheters 3%
Peripheralcatheters 2%
Cauteryburnsorfires 2%
Anaesthesia-gas-deliveryequipment 1%
Patientwarmingdevices 1%
Hotbottleburns 1%
Medication(n¼338)
Adversedrugreaction 3%
Wrongdrugordose 3%
InadequateanalgesiafromMACorGA 2%
MAC¼monitoredanaesthesiacare;GA¼generalanaesthesia.
Mostcommoneventsinanaesthesiaclaimsthatoccurredin1990orlater(n¼4549).
Claimsforchronicpain(n¼681)excluded.Claimsformiscellaneouseventsineach
majorcategorynotshown.Percentagesmaysumtogreaterthanoverallcategory
percentagesduetorounding.
1970-1989 (n=1043)
%) 30% 1990-2007 (n=864)
od ( ** **
eri
p
e
m
n ti 20%
ms i * *
ai
y cl
or
at 10%
pir
s
e
of r
n
o
orti 0%
p
o Oesophageal Intubation Inadequate Difficult Intubation Aspiration
Pr Oxygenation/Ventilation
Fig.6. Changesinrespiratoryeventsovertime.*p<0.001,1970–89vs1990–07;**p<0.05,1970–89vs1990–07.Excerptedfrom
Ref.10Newtrendsinadverserespiratoryevents,ASANewsletter2011;75(2):28–29oftheAmericanSocietyofAnesthesiologists.
AcopyofthefulltextcanbeobtainedfromASA,520N.NorthwestHighway,ParkRidge,Illinois60058-2573.
270 J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276
pneumothorax.Pressurewaveformmonitoring,useofultrasoundguidancefordifficultcatheterisation,
andcheckingandactingonachestradiographaftervascularcatheterinsertionwerenotedaspotential
actionstoreducepatientinjuryassociatedwithcentralvenouscatheters.16
PeripheralI.V.andarterialvascularcannulationcomplicationsweremostcommonlyassociatedwith
cardiacsurgeryprocedureswithtuckedarms,preventingvisualcheckingforpropercatheterposition
andfunction.17 HalfofI.V. claimsresultedfromextravasationofdrugsorfluids,sometimescausing
severetissuedamage.Therewereremarkablyfewclaimsassociatedwithradialarterycannulation.17
Otherequipmentproblemsincludedcauteryburnsorfires(2%)andburnsfrompatientwarming
devices(1%)orhotbottlesusedtowarmorpositionpatients(1%).Warmingdeviceclaimswereoften
associated with misuse of equipment, such as separating a hose from a forced-air warming device.
Claimsassociatedwithhotbottlesusedtowarmorpositionpatients18appearedtodeclinewiththe
introductionofforced-airwarmingdevices,althoughsporadicinjuriescontinuetooccur.Firesasso-
ciatedwithcauteryuseduringMACrepresented2%ofclaimsin1990–2007andwillbediscussedin
moredetaillater.
Medicationproblemsrepresented7%ofanaesthesiaclaimsin1990–2007.Theseclaimswerefairly
equallydistributedbetweenadversedrugreactionsandmedicationerrors.Medicationmanagement
forchronicpainwasanimportantpatientsafetyissueinmorerecentclaims,andwillbepresentedin
detail lateron. The most common medication errors during surgical and obstetric anaesthesia care
wereincorrectdosageanddrugsubstitutionerrors.19Drugsubstitutionerrorsincludedbothsyringe
swapsandinfusionswaps.Vasopressorsandmusclerelaxantswerethemostcommonmedications
involvedinmedicationerrorclaims.Mostmedicationerrorswereconsideredpreventable,andthey
resultedinahighproportionofbraininjurytopatients.
Clinicallessonslearned
Adverseeventsandinjuriesassociatedwithmanagementofthedifficultairway
Ananalysisofclosedclaimsinthemanagementofthedifficultairwayrevealedthatdifficultairways
arosethroughouttheperioperativeperiod:67%oninduction,15%duringsurgery,12%onextubation
and5%duringrecovery.20Duringairwayemergencies,persistentintubationattemptswereassociated
withdeathorpermanentbraindamage.20Thelaryngealmaskairway(LMA)wasnotaneffectiverescue
techniqueinsomeclaimsinwhichmultipleprolongedattemptsatconventionalintubationweremade.
TheClosedClaimsdataemphasisethattheLMAcannotbeconsideredafail-safeforthedifficultairway,
particularly when there is infraglottic obstruction or swelling/trauma of the airwaywith persistent
intubationattempts.TheClosedClaimsdatasuggestthatasurgicalairwayshouldbeinstitutedearlyin
themanagementofadifficultairway.Deathandpermanentbraindamagefromdifficultintubationat
inductionofanaesthesiahavedeclinedsinceadoptionoftheASApracticeguidelinesformanagement
ofthedifficultairway.20However,managementofthedifficultairwayatextubationandotherphases
ofanaesthesiacareremainsasignificantanaesthesiapatientsafetyissue.Thisfindingsuggeststhat
newstrategiesthatfocusuponextubationofthedifficultairwayarenecessary.
Practicepoints
(cid:2) Difficultairwayscanbeencounteredthroughoutanaesthesiacare,notjustoninductionof
anaesthesia.
(cid:2) Persistentintubationattemptsinairwayemergencieswereassociatedwithpooroutcomes.
Limitconventionalattemptstothreebeforeusingotherstrategies.
(cid:2) TheLMAisnotafail-safeintherescueofadifficultairwayinthepresence ofinfraglottic
obstructionorpersistentintubationattempts.
(cid:2) Asurgicalairwayshouldbeinstitutedearlyinthemanagementofthedifficultairway.
(cid:2) Developmentofadditionalmanagementstrategiesfordifficultairwaysencounteredduring
maintenance,emergenceorrecoverymayimprovepatientsafety.
J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276 271
AdverseeventsandinjuriesassociatedwithMAC
Aspointedoutearlier,claimsassociatedwithMACpracticesignifyagrowingareaofliabilityforthe
anaesthesiologist.AnanalysisoftheClosedClaimsdatabasebyBhanankeretal.11shedslightonthe
causesandmechanismsofinjuryencounteredduringMAC.
Respiratoryevents
Respiratory depression as a direct consequence of anaesthetic overdose was the most specific
mechanism of injury and accounted for 21% of MAC claims.11 Drug combinations (propofol plus
benzodiazepines or opioids) were involved in over half of the cases of oversedation. Many of the
patientsinvolvedwereelderly,ASAphysicalstatus3–5and/orobese.Thecarewasjudgedsubstandard
inthemajorityofcasesandpreventablewithbettermonitoring,includingpulseoximetry,end-tidal
capnographyorboth.
Practicepoints
(cid:2) MACcanimposeachallengetotheanaesthesiologist,particularlyinvulnerablepatients.
(cid:2) Inadequateoxygenation/ventilationrelatedtosedative/analgesicoverdosecontributestothe
majorityofuntowardevents.
(cid:2) Continuousmonitoringofventilationandoxygenation,andvigilanceinrecognisingimmi-
nentrespiratoryadverseeventsaremandatoryduringMACcases.Useofend-tidalcapnog-
raphy to monitor ventilation is particularly important, as oxygen saturation is slow to
decreaseinthepresenceofsupplementaloxygen.
Burninjuries
On-the-patient operating-room fires accounted for nearly a fifth of MAC claims, but only 1% of
generalanaesthesiaandlessthan1%ofregionalanaesthesiaclaims.11MACclaimsassociatedwithfire
almostalwaysoccurredinthesettingofsurgeryonthehead,faceandneck.Inallcases,anelectro-
cautery and supplemental oxygen were used. It is important to understand the fire triad: ignition
source (cautery), oxidiser (supplemental oxygen) and fuel (drapes and/or alcohol prep) (Fig. 7).1
Supplementaloxygenisunderanaesthesiacontrol,andgreatlycontributestoadramaticandrapidfire.
The ASA developed a practice advisory for the prevention and management of operating-room
fires.21Therecommendationsemphasisetheimportanceofcommunicationbetweenthesurgeonand
theanaesthesiateamregardingthetimingofuseoftheelectrocautery.Thesurgeonmustgiveadequate
noticeforusetoallowtheanaesthesiateamtostopdeliveryofoxygenandwaitseveralminutesbefore
Fig.7. On-patientfiresduringmonitoredanaesthesiacare.
272 J.Metzneretal./BestPractice&ResearchClinicalAnaesthesiology25(2011)263–276
cauterisation.Thedrapesshouldbeopentotheroomtoavoidaccumulationofhighconcentrationsof
oxygen under them. If moderate or deep sedation is required, general anaesthesia with a sealed
deliverydevice(e.g.,LMAorendotrachealtube)shouldbeconsidered.
Practicepoints
(cid:2) Aimforlightsedationtoavoidneedforsupplementaloxygenforheadandneckprocedures.
(cid:2) Considerasealeddeliverydevice(LMAorendotrachealtube),ifmoderateordeepsedationis
required.
(cid:2) Thesurgeonshouldgiveadequatenoticeforuseofthecautery.Theanaesthesiateamshould
stopdeliveryofoxygenandwaitforseveralminutes.
(cid:2) Avoiddeliveryofoxygenunderdrapes.
Adverseeventsandinjuriesassociatedwithanaesthesiaatremotelocations
Anaesthesia outside the traditional operating-room setting continues to represent a challenging
fieldandagrowingareaofliabilityfortheanaesthesiologist.Arecentclosedclaimsstudy12examined
patterns of injuryand liability related to 87 claims encountered in remote locations and compared
themtothoseofoperating-roomclaims.Mostremotelocationclaimsoccurredinthegastroenterology
suite,cardiaclaboremergencydepartmentandinvolvedahighpercentageofelderlyandmedically
complexpatients.
Adverserespiratoryeventsweretheleadingcauseofbadoutcomes,includingdeathandpermanent
braindamage,andoccurredtwiceasofteninremotelocations comparedwiththeoperatingroom.
Inadequateoxygenation/ventilationwasthemostcommondamagingevent,followedbyequipment
failure/malfunction and cardiovascular events. MAC was performed in one-half of the procedures.
Respiratory depression secondary to oversedation during MAC accounted for over 30% of remote
location claims. Polypharmacy and substandard monitoring of oxygenation and ventilation showed
similar patterns, as described previously. Disturbingly, in 15% of the cases, monitoring with pulse
oximetry was absent and capnography was used in only four patients.12 Reviewers judged care in
remotelocationclaimsasbeingsubstandardin54%andpreventablewithbettermonitoringin32%of
cases.12
Practicepoints
(cid:2) Therisksassociatedwithanaesthesiaatremotelocationscannotbeunderscoredenough.
(cid:2) As compared with general operating-room anaesthesia claims, remote location claims are
associatedwithmoresevereinjuries,withdeathandbraindamagecommon.
(cid:2) Adherencetouniformstandardsinrespiratorymonitoringiscritical.Useofend-tidalcap-
nographyisespeciallyrecommendedtomonitorventilation.
Adverseeventsandinjuriesassociatedwithobstetricanaesthesia
AnanalysisofclosedclaimsinobstetricanaesthesiabyChadwicketal.in1991identifiedsevere
injuries, such as maternal death and newborn death/brain damage as contributing to the largest
numberofclaims.22 In a morerecentreview, newborn death/brain damage still constituted a large
numberofclaims(21%),butmaternalnerveinjuries(21%),whichwerelargelytemporaryandnon-
disabling,emergedasasignificantsourceofmalpracticeclaims.23Allbutoneofthenerveinjuriesin