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