Analysis of prehospital perimortem caesarean deliveries performed by Helicopter Emergency Medical Services in the Netherlands and recommendations for the future

Clinical

paper

Analysis

of

prehospital

perimortem

caesarean

deliveries

performed

by

Helicopter

Emergency

Medical

Services

in

the

Netherlands

and

recommendations

for

the

future

XRJ

Moors

*

,

TH

Biesheuvel

,

J

Cornette

,

MG

Van

Vledder

,

A

Veen

,

M

de

Quelerij

,

EEM

Weelink

,

JJ

Duvekot

a_{DepartmentofAnaesthesiology,ErasmusMC,UniversityMedicalCenterRotterdam-SophiaChildren’sHospital,Rotterdam,TheNetherlands} b_{HEMS,ErasmusUniversityMedicalCenter,Rotterdam,TheNetherlands}

c

DepartmentofSurgeryandHEMS,VUUniversityMedicalCenter,Amsterdam,TheNetherlands

d

DepartmentofObstetricsandGynaecology,ErasmusUniversityMedicalCenter,Rotterdam,TheNetherlands

e

TraumaResearchUnit,DepartmentofSurgeryErasmusMC,UniversityMedicalCenterRotterdam,Rotterdam,TheNetherlands

f_{DepartmentofAnaesthesiology,FranciscusHospitalRotterdam,TheNetherlands}

g_{DepartmentofAnaesthesiologyandHEMS,UniversityMedicalCenterGroningen,UniversityofGroningen,TheNetherlands}

Abstract

Background:Prehospitalperimortemcaesareandelivery(PCD)isararelyperformedprocedure.Inthisstudy,weaimedtoexamineallPCDs performedbythefourHelicopter EmergencyMedicalServicesintheNetherlands;todescribetheprocedures,outcomes,complications,and compliancewiththerecommendedguidelines;andtoformulaterecommendations.

Methods:Weperformedapopulation-basedretrospectivecohortstudyofallconsecutivematernalout-of-hospitalcardiacarreststhatunderwentPCD intheprehospitalsettingbetweenMay1995andDecember2019.Registereddataincludedpatientdemographics,operatorbackground,advancedlife supportinterventions,andtimelines.Resuscitationperformancewasevaluatedaccordingtothe2015EuropeanResuscitationGuidelines. Results:SevenpatientsunderwentaprehospitalPCD.Threemothersdiedonthescene,whilefourweretransportedtoahospitalbutdiedinthe hospital.SevenneonateswerebornbyPCD.Oneneonatediedonthesceneandsixweretransportedtoahospital.Threeneonateswereeventually dischargedfromthehospital.Amongthethreesurvivingneonates,theperiodsfromdispatchtostartofPCDwere13,14,and21min.

Conclusions:TherewasalowincidenceofmaternalperimortemcaesareandeliveriesinTheNetherlands.OnlysomeneonatessurvivedafterPCD.It isrecommendedthatPCDbeperformedasquicklyaspossible.Duetothedelay,themotherhasafarlowerchanceofsurvivalthantheneonate.Infatal cases,autopsyisstronglyrecommended.

Keywords:Helicopteremergencymedicalservice,Perimortemcaesareandelivery,Maternalarrest,Resuscitativehysterotomy,Prehospital

* Correspondingauthorat:ErasmusUniversityMedicalCenter SophiaChildren’sHospital,DepartmentofAnaesthesiology,P.O.Box2060,3015CN Rotterdam,TheNetherlands.

E-mailaddress:x.moors@erasmusmc.nl(X.Moors).

https://doi.org/10.1016/j.resuscitation.2020.07.023

Received18April2020;Receivedinrevisedform8July2020;Accepted19July2020 Availableonlinexxx

Available

online

at

www.sciencedirect.com

Resuscitation

Introduction

Little is known about the success rates and complications of prehospitalperimortemcaesareandeliveries(PCDs)performedby physician-led Helicopter Emergency Medical Services (HEMS). Onlytwostudieshaveexaminedtheincidenceofmaternalcardiac arrest in the out-of-hospital setting.1,2 _{Few obstetrical providers}

encounter in-hospital acute maternal cardiopulmonary arrest (MCPA), and even fewer prehospital providers. However, the incidence of PCDs is increasing in the Netherlands.3 There is currentlynospecifictermforcaesareandeliveryduringMCPA.The termPCDwasintroducedin1986,6_{andwasadoptedbyboththe}

Society for Obstetric Anesthesiology7 _{and the American Heart}

Association.

Intheeventofcardiacarrestduringpregnancy,PCDisconsidered essentialforresuscitationofboththemotherandfetus.PCDshould onlybeperformedfrom20weeksofpregnancybutpreferablyfrom24/ 26weekswhenthepregnantuteruscompressestheinferiorcaval vein.ItisrecommendedthatPCDbestartedafterfourminutesand performedwithinthenextminute,tomaximizethechancesofreturnof spontaneous circulation(ROSC) through caval relief and uterine autotransfusion. Although PCD is nota complex procedure, the cognitive,operational,andemotionalcircumstancesmakeitdifficult, especiallyintheprehospitalsetting.Knowledgeandperformanceof resuscitationtechniquesthataccountforapregnantwoman’sunique physiologyarecrucialtomaximizethechancesofsurvivalforboththe motherandfetus.4_{TheAHAissuedascientificstatementonmaternal}

cardiopulmonaryarrest,statingthatthereisinsufficientevidenceto supportprehospitalPCD,andthatprehospitalprovidersshouldnotbe expectedtoperformPCDduetothelimitedresourcesavailableto perform advanced life support and lack of adequately trained personnel.5 _{However, in 2019, theParis Brigade Cardiac Arrest}

GroupreportedthatprehospitalPCDcouldimprovetheprobabilityof the mother_’s survival,2 _{highlighting the controversy amongst}

specialists.

In1995,HEMSwasintroducedintheNetherlands,enablingthe rapiddeliveryofamedicalteamtothescene,inadditiontotheregular ambulance crew. A HEMS team comprises a physician (board-certified anesthesiologist or trauma surgeon), specialized nurse (paramedicorregisterednursefromtheemergencydepartment),and helicopterpilot.HEMSpersonnelreceiveadditionaltraining,suchas managingobstetricemergenciesandtrauma(MOET),andannually practicesurgicalskillsinacadaverlab.Onaverage,HEMSisairborne withintwominutesafterdispatchindaylight,andwithinfiveminutesat nighttime. The average flying times rangefrom 8 to 13minutes, dependingonwhichHEMSisactivated.

Inthisretrospectivestudy,weaimedtodescribetheexperienceof HEMS with PCD; to report PCD outcomes, complications, and compliancewithrecommendedguidelines;andtomake recommen-dationsforthefuture.

Methods

Ethicsapproval

This retrospective study was approved by the Medical Ethical CommitteeoftheErasmusUniversity MedicalCenter(MEC-2019

0277).

Studydesign

WeperformedaretrospectiveanalysisofallfourHEMSdatabases from May 1, 1995 (the start of HEMS in The Netherlands) until December2019.WeidentifiedallcasesinvolvingPCD,andcollected informationaboutthesecasesfromthedatabase.Wefurtherasked each individual doctor who performed a PCD to complete a questionnaire regarding personal skillsand experience,and data missingfromthedatabase.

Studysetting

TheNetherlandshasapopulationofover17millionpeople,covering an area of 42 508 km2_{. There are four HEMS teams in the}

Netherlands—eachcoveringoneoffourareasofthecountry.HEMS actsinclosecollaborationwithemergencymedicalservices(EMS), andfollowsthesamemedicalprotocols.Pregnantpatientsconstitute <1%ofallcalls,suchthatexpertiseandexperiencearelimited.Since June 2013, anationwide protocol dictates that HEMS is always dispatchedtogetherwithEMSincasesofcardiacarrestinapregnant woman.

Selectionofparticipants

Weidentifiedallpatientswhowerepregnantandincardiacarrest betweenMay1995andDecember2019,andanalyzedtheavailable data,includingpatientdemographics, complications,andoperator background.Wealsoevaluatedcompliancewiththeguidelinesfor managingobstetricemergenciesandtrauma(MOET),whicharenow part of the European Resuscitation Guidelines issued in 2015.8

Availablematernal-specificresuscitationbenchmarksbasedonthe maternal algorithm included intravenous placement above the diaphragm,advancedairwayinsertion,timelyperimortemcaesarean delivery(startedwithinfourminutesofwitnessedarrest,andachieved withinoneminute),typeofincision(midlineorlowertransverse),and initial cardiac rhythmfor pregnancies of _>20 gestational weeks. Missing data are reported as unknown in the results. Pregnant patientswithagestationalageoflessthan20weeksorwhowere quicklytransferredtoahospitaltoundergoPCDintheemergency departmentwereexcluded.

The study isregistered undernumber MEC-2019 0277, and approvedbytheInstitutionalReviewBoardoftheErasmusMC.

Results

Prehospitalpopulationandclinicalcharacteristicsof pregnantwomen

SincethestartofHEMSin1995,allfourHEMSstationshavereceived over80000calls,ofwhicharound35000werecanceledbyEMSprior toarriving.Thus,HEMShastreatedapproximately45000patients. These cases included seven pregnant women with prehospital cardiacarrest,inthreeofthefourHEMSareas.

Timelines

Forallpregnantwomenwhowereincardiacarrest,HEMSwascalled togetherwithEMStoensurerapidassistance.Table2showsthe periodfromdispatchtostartofPCD,whichincludesstartingtime,

flyingtime,timetoarriveatthescenefromthelandinglocation,and initiating the actual PCD. In all seven cases, CPR was initially performedbybystanders,policemen,orEMS.WhenHEMSarrivedat thescene, theyimmediately startedthe PCD because basic life supportandadvancedlifesupporthadalreadybeenprovidedbyEMS. NoneofthewomenwastransportedtoperformPCDinhospital.

Maternalcharacteristicsandoutcome

Thesevenpregnantwomenhadamedianageof29.6years(range, 18 38years)andwereallinthelasttrimesterofpregnancy(range, 31 weeks and 4 days to nearly 42 weeks). All had singleton pregnancies. Only one mother was obese (estimated weight of 140kg).Noneofthemothershadcomorbiditiesdocumentedinthe HEMSdatabase(Tables1and2).

Of the seven women who underwent a PCD, three were pronounceddeadonthescene.Theremainingfourwomenwere transportedtoahospital,twoofwhomexhibitedROSCatthescene. Noneofthefourwomenwhowereadmittedtoahospitalsurvived.One womandiedintheemergencydepartment,oneintheoperatingroom,

andtwointheintensivecareunit(bothafterfivedaysanddueto severeasphyxia).

Fetaloutcomeandneonatalsurvival

SevenneonateswerebornbyPCD.Oneneonatediedonthescene, andtheothersixweretransportedtothehospital.Ofthesixneonates admittedtoahospital,threediedinthepediatricintensivecareunitas aconsequenceofsevereasphyxia.Theremainingthreebabieswere discharged fromthehospital:two(casesfiveandseven)ingood neurologicalcondition,andtheother(casetwo)infairneurological condition(at22monthsofage,thepatientcancrawlandstandup,but doesn't talk). The three surviving neonates were born after the performanceofPCDat13,14,and21minafterdispatch(Table3).

Cardiacarrestcharacteristics

Onewomanwentintocardiacarrestafteracaraccident.Allseven womenhadanon-shockablerhythmuponinitialrhythmcheckbyEMS orHEMS:fiveinasystole,andtwowithpulselesselectricalactivity

Table1–DescriptionofcasesOHCA:out-of-hospitalcardiacarrest;PCD:perimortemcaesareandelivery;ROSC:return ofspontaneouscirculation;ED:emergencydepartment;PICU:pediatricintensivecareunit;ICU:intensivecare unit;CPR:cardio-pulmonaryresuscitation.

Nr Year,age,obstetric history,andweeks pregnant

Courseofevents Discharge

fromhospital mother/child

1 2003,31years,G1P0, 390/7

Roadtrafficaccidentwhileunrestrainedinthefrontpassengerseat.At11minafterOHCA,PCD wasperformedviaPfannenstielincision,whichtook2min.Bothmotherandchildgained ROSC,andwerethentransportedtoahospital.Themotherdiedthesamedayintheoperating roomfollowingmassivetransfusion.Thebabydied3dayslaterinthePICUduetosevere neurologicalproblems.

/

2 2014,30years,G4P3, 384/7

OHCAduetoamnioticfluidembolism.At21minafterstartingCPR,PCDwasperformedvia Pfannensthielincision,whichtook4 5min.Themotherdidnotregainapulsebutwas transportedtotheEDanddeclareddeadsoonafterarrival.ThebabygainedROSCat2min afterbirth,stayed11daysinthePICU,andwaseventuallydischargedfromthehospital.At 2yearsofage,thepatientisinfairneurologicalcondition,cancrawlandstandwithnohelp,but isnottalkingyet.

/+

3 2015,18years,G1P0,32 UnknownOHCAorigin.At18minafterstartingCPR,PCDwasperformedviamedianincision, whichtook1min.BothmotherandbabydidnotgainROSC,diedintheprehospitalsetting,and werenottransportedtothehospital.

/

4 2015,32years,G3P2, 416/7

OHCAduetoamnioticfluidembolism.At27minafterstartingCPR,PCDwasperformedvia medianincision,whichtook1min.ThemotherhadROSC30minafterstartingCPR,andwas transportedtoahospital.After5daysintheICU,themotherdiedduetoneurologicalproblems. ThebabyhadROSC20minafterPCDwasperformed,andwastransportedtoahospital.After 2daysinthePICU,thebabydiedduetoneurologicalproblems.

/

5 2015,38years,G2P1,37 UncertaincauseofOHCA.Massivevaginalbleedingoccurred,likelyduetoplacentaprevia.At 14minafterstartingCPR,PCDwasperformedviamedianincision,whichtook1min.The motherdiedatthesceneduetobloodloss.ThebabyhadROSCat9minafterstartingPCD. After6daysinthePICU,thebabywasdischargedfromthehospitalingoodneurological condition.

/+

6 2018,28years,G3P2, 355/7

OHCAduetolungembolism(confirmedbyCT).At32minafterOHCA,PCDwasperformedvia medianincision,whichtook1min.Themotherwastransportedtoahospitalwhilereceiving CPRandwithVF,andgainedROSCinthehospital>1hafterCPRinitiation.Shewasadmitted, anddiedafter5daysintheICU.ThebabygainedROSC1minafterPCD,andwastransported tothehospital.After5daysinthePICU,thebabydiedduetoneurologicalproblems.

/

7 2019,30years,G3P1, 314/7

OHCAduetolungembolism(confirmedbyautopsy).At18minafterOHCA,PCDwas performedviamedianincision,whichtook1min.ThemothernevergainedROSCanddiedon thescene.ThebabygainedROSC12minafterPCDandwastransportedtothehospital.After 3daysinthePICU,MRIshowednohypoxiclesions.After8daysinthePICU,thebabywas dischargedfromthehospitalingoodneurologicalcondition.

Table 2– Maternal characteristics ROSC: return of spontaneous circulation; EMS: emergency medical service; HEMS: Helicopter Emergency Medical Service; RTA: road traffic accident; N.A.: not applicable.

Case 1 2 3 4 5 6 7

Year 2003 2014 2015 2015 2015 2018 2019

Parity G1P0 G4P3 G1P0 G3P2 G2P1 G3P2 G3P1

Mother’s age, years 31 30 18 32 38 28 30

Incision Lower transverse

abdominal

Lower transverse abdominal

Midline Midline Midline Midline Midline

Surgeon Anesthesiologist Trauma Surgeon Anesthesiologist Anesthesiologist Anesthesiologist Anesthesiologist Trauma Surgeon

Procedure duration, minutes 2 4 5 1 1 1 1 1

Gestational age, weeks 39 0/7 38 4/7 +/-32 41 6/7 37? /7 35 5/7 31 4/7

CPR + + + + + + +

1st Rhythm asystole asystole asystole PEA asystole PEA Asystole

Diagnoses Trauma RTA Amniotic fluid embolism

Unknown Amniotic fluid embolism Uncertain, but vaginal bleeding Pulmonary embolism Pulmonary embolism Obduction/CT performed /+ / / /+ +/ /+ +/

Time to ROSC (minutes) 28 30 >45

Survival

Time from dispatch to start of procedure 11 21 18 27 14 32 13

Transport to hospital Y Y N Y N Y N

Left lateral tilt (upon HEMS arrival) Y N Y N N Y N

Intubation HEMS EMS EMS First i-Gel by EMS,

intubated by HEMS

No EMS HEMS

Comorbidity n.a. n.a. n.a. n.a. n.a. n.a. n.a.

(PEA).FourwomennevergainedROSC,twowomenexhibitedROSC atthescene,andoneshowedROSCattheemergencyroomafter overonehourofCPR.Noneofthewomenweredischargedfromthe hospital.PostmortemCTscanningwasperformedinonlythreecases. Amongthethreewomenwhowerenottransportedtoahospital,only onereceivedanautopsyandadiagnosis(caseseven).Inonecase, no autopsy was performed. In the other case, an autopsy was performedfivedaysafterdeath,andnodistinctdiagnosiswasmade thatcouldexplainthecardiacarrest.

AllsevenneonatesreceivedCPRatbirth.Sixneonatesgained ROSC, of whomfour showed ROSC withinfive minutes orless (includingtwoneonateswhoweredischargedfromthehospital).On thescene,itwasdifficulttoassesswhetherapulsewaspresent(for example,duetobadlightingornoise);thus,insomecases,CPRwas initiated but stopped after ultrasound confirmation of heart contractions.

Guidelinecompliance

ParamedicsarenotallowedtoperformPCD;therefore,PCDcouldnot beinitiateduntilHEMSarrived.Inallcases,CPRwasstartedbyEMS orbystanders.Notallwomenreceivedendotrachealintubation.Three motherswereintubatedbyEMS,onebyHEMS,onehadalaryngeal maskairway(i-Gel©)insertedbyEMSandwas intubatedbythe HEMSphysicianuponarrival, andonewasventilated using bag-valve-maskventilation.Allwomenhadanintravenousaccessabove thediaphragminonearm.Allwomenreceivedadrenalineaccording toprotocol.Onlyonewomandevelopedventricularfibrillationandwas shockedfourtimesduringCPR(casesix).Theperiodfromdispatchto PCDinitiationwaswellovertenminutes,withamaximumof32min. All median incision procedures took approximately one minute toperform.Incisionbylowertransverseabdominalincision (Pfannen-stielincision)tooklonger:twotofiveminutes.Infourwomen,EMSor bystandersdid notapplymanualuterus displacement,whichwas correctedbyHEMSuponarrival.

Debriefing

ItisroutinetohaveadebriefingafterreturningtotheHEMSstation withtheteam.Inallthedescribedcasesdebriefingsandperinatal auditswereheldforallinvolvedhealthcareproviders.

Discussion

AccordingtothenationwidedatabaseoftheDutchHeart Associa-tion,9_{8000out-of-hospitalcardiacarrestsoccureachyear,including}

only afew in pregnant women.10 In thisretrospective study, we describeallsevenperimortemcaesareandeliveries(PCD)performed byHEMSinTheNetherlandsbetween1995 2019.

WefoundthatthetimefromdispatchtoPCDinitiation(Table2)was wellovertherecommended4 5min.11_{ItisdifficulttoperformPCD}

withinfiveminutesaftercardiacarrest,especiallyintheprehospital setting,8,12_{andthiscriterioncannotalwaysbemetevenforin-hospital}

PCDs.3,11In ourpresent study,amongthe threeneonates whosurvived, thetimesuntilPCDinitiationwere13,14,and21min—wellbeyondthe recommended4 5min.Intheprehospitalsetting,thetargetof4 5min isnotfeasiblesincemedicalemergencyunitsalwaystakemoretimeto arrive, even HEMS. Nevertheless, we recommend that PCD be performedassoonastechnicallypossible.Althoughmaternalsurvival israreafter>14min,thereisstillachanceofneonatalsurvival,andno dangeroffurthermaternaldamage.Onecouldarguethat maternal survivalmightbeimprovedifPCDwereperformedbyparamedicswho arrive atthe scene earlier;however,paramedics have no surgical experienceandare notauthorizedtoperformthisprocedure.Inall seven patients,uponHEMSarrival,CPRhadbeenstartedbyEMSorstarted by bystandersandtakenoverbyEMS.Fourwomenwere already intubated,andallwomenhadanintravenousaccessabovediaphragm. Allpatientsinitiallyhadanon-shockablerhythm.HEMSwasableto immediatelystartPCDuponarrivalinallcases.

In 2015,the AmericanHeartAssociation5 released ascientific statementindicatingthatprehospitalPCDshouldnotbeperformeddue tothe lackofadequatelytrainedpersonnel,andthatfocusshould insteadbeonprovidingbasicandadvancedlifesupport,andquick transporttoafacilitythatcanperformPCD.In2019,theParisBrigade CardiacArrestWorkGroupdescribed16pregnantpatientsinOHCA, and reported thatprehospital PCDimproved the likelihood of the mother’ssurvival.2 They alsostated thatbasic andadvanced life supportarewarrantedwhenPCDcanbeperformedbyatraineddoctor. In ouropinion,theEMS teamsin theNetherlands can securetheairway, insertanintravenousaccesscannula,providemedicationaccordingto the nationwide advanced life support protocol and, if necessary, defibrillatethepatient—whileHEMScanquicklyperformthePCD.

Braindamagebeginsafterfiveminutesofanoxia.Underthe4-to 5-minuteguideline,PCDistobeinitiatedatfourminutes,andbe completedinatimelymanner(withinoneminute)todeliverthefetus priortotheoccurrenceofbraindamage.Ifawomanhasaresuscitable cardiacarrest,herlifemayalsobesavedbyapromptandtimelyPCD duringCPR.Aneonatecansurviveandremainingoodneurological conditionafteralongerperiodofanoxia.AsmallBritishstudyreveals thatneonataldamageordeathwillnotoccuruntilaftera20-minute period of anoxia.13 Inthe CAPSstudy,14 maternalsurvivalrates depended on the time from collapse to the start of in-hospital perimortem caesareandelivery.Pregnant patientsreceiving CPR who underwent in-hospital perimortem caesarean delivery and survivedallhadtheirperimortemcaesareandeliverywithin12min. IntheNetherlands,Dijkmanreportednosurvivalofpregnantpatients when ittooklonger than 14min tostart in-hospital PCD.3 Inthe prehospitalenvironment,itisdifficulttoarriveontimetostartPCD within12 14min.

Table3_–NeonatalcharacteristicsCPR:cardiopulmonaryresuscitation;ROSC:returnofspontaneouscirculation;HEMS: HelicopterEmergencyMedicalService.

Case1 Case2 Case3 Case4 Case5 Case6 Case7

Baby’sweight,grams 3500 4000 1500 2000 4300 +/ 3000 2620 1900

CPRatbirth + + + + + + +

ROSC/TimetoROSC +/5 +/2 / +/20 +/4 +/1 +/12

Dischargefromhospital + + +

ThetimingofperformingaPCDisquiteimportantforthesurvivalof bothmotherandfetus.ArecentBritishstudydescribesadecreaseof maternalsurvivaldependingontheintervalbetweencardiacarrestand PCD14.InthisstudythesurvivorshadaPCDbetween0and39minafter their cardiac arrests. The median interval of the cardiac arrest/PCD period betweensurvivorsandthosewhodiedwasrespectively3and12min. Thissamearticlefoundthatmaternalsurvivaldoubledinwomenthat werenottransportedtoanotherplacetoperformthePCD.Theneonatal survival decreases after an interval of more than five minutes. In the British studythedifferenceinsurvivalis96%ifdeliveredwithin5minand70%if deliveredaftermorethanfiveminutes.Anoverviewoftheimportanceof theintervaltimeisalsogiveninthereviewarticlebyZelopetal15_.

Thecauseofcardiacarrestcouldbedeterminedinonlyfivecases inourstudy.Westronglyrecommendthatthisdiagnosisbeobtained throughCTorMRIscanningand/orautopsy.Elucidatingthecauseis importantfordeterminingwhywomendie,topotentiallyadjusttraining andcreateawarenessamongstdoctorsandnurses.Furthermore,in individualcases,adiagnosismayrevealwhyresuscitationwasnot successful.Rarely,autopsymayleadtotheidentificationofpreviously unknowninheriteddiseases.Finally,elucidationofthecauseofdeath mayprovidesomeconsolationtotherelatives.Insomecountries, autopsyisobligatoryforpregnantwomen;forexample,ithasbeen compulsoryinSriLankasince2008.

Although obstetricians might be more comfortable with lower transverseabdominalincisions,amidlineincisionmayberecommended insomecases,especiallyforcareprovidershavinglessexperiencedwith lowertransversecaesareansection.Notably,inourstudy,eventhe trauma surgeontook alonger timetoperform PCDusing alower transverseabdominal incision. The midline procedure is technically easier because the abdominal wall is thinner, the resistance and structuresintheabdominalwallaresimpler,andtheuterusisalways immediatelyencountereduponcuttingthroughtheabdominalwall— therebyprotectingotherstructures,suchasthebladderandbowel.Inthis study,allPCDsperformedviamedianincisiontooklesstimethanthose performed via lower transverse abdominal (Pfannenstiel) incision

(Table2).Usingaverticalmidlinelaparotomyincisionwillmaximize

exposureandallowthegreatestaccesstofacilitatetheprocedure,16and isthusrecommended.After deliveryoftheneonateand cuttingthe umbilicalcord,theplacentamaybeleftinplaceormanuallyremoved. In The Netherlands, the Managing Obstetric Emergencies and Trauma(MOET)coursestartedinDecember2003.Duringtheearly yearsofHEMSinThe Netherlands,obstetricemergencieswerenotinthe dispatchprotocols.ThischangedinJune2013,whenthenationwide protocol for HEMS activation was adjusted, with the addition of complications during birth or pregnancy. In these cases, HEMS is primarilyactivated,togetherwithEMS.Thismayexplainwhyalmostall PCDs in our study were performed during the last five years. The first PCD wasafteracaraccident,whichisaprimaryHEMSdeploymentcriterion.

Conclusions

and

recommendations

Thiswasthefirststudytoreporttheoutcomesofacohortofpregnant woman who suffered out-of-hospital cardiac arrest, and received prehospitaltreatmentbyphysician-ledHEMSinTheNetherlands.We foundalowincidenceofPCDsduringmaternalout-of-hospitalcardiac arrests.Intheprehospitalsetting,evenwithHEMSavailability,the4-to 5-minute guideline was not achieved in any case. While we still recommendthatperimortemcaesareandeliverybeperformedasearly aspossible,onemustrealizethatthedelayintheprehospitalsetting

meansthatthelikelihoodofsavingthemotherisfarlowerthanthatof savingthe neonate.InprehospitalresuscitationsandPCD,special attentionshouldbepaidtoperformingintubation(withcapnography), manualuterinedisplacementtoavoidaortocavalcompression,and usingamidlineratherthanalowertransverse(Pfannenstiel)incision. Incasesofmaternaldeath,autopsyisstronglyrecommendedto identifythecauseofcardiacarrestandtounderstandthefailureofthe procedure.Cardiacarrestissorare,especiallyinyoungwomen,thatit ismandatorytoinvestigateitscauseasthoroughlyaspossible.If autopsyisnotallowedorrefused,afull-bodyMRIorCTscanmay serveasanalternative.

Creditauthor

Enclosed,pleasefindouroriginalarticle:“Analysisofall out-of-hospital perimortemcaesareandeliveriesperformed byHelicopter EmergencyMedicalServicesinTheNetherlandsand recommenda-tionsforthefuture”,whichwewouldlikeyoutoconsiderforpublication inResuscitation.

All authors have made substantial contributions to all of the following:(1)theconceptionanddesignofthestudy,oracquisitionof data,oranalysisandinterpretationofdata,(2)draftingthearticleor revisingitcriticallyforimportantintellectualcontent,(3)finalapproval oftheversiontobesubmitted.

Conflicts

of

interest

None.

This research projectdid not receive any specific grant from fundingagenciesinthepublic,commercial,ornot-for-profitsectors.

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