Andersons pediatric cardiology 2095

AKIstages.Aretrospectivepediatricstudyofover500infantsaftercardiac
surgeryassessedaversionoftheFST,whereUOPwasassessedat2and6hours
afteradiureticchallenge.34ThisstudyfoundthatpatientswhohadUOPofat
least1mL/kgperhourwereveryunlikelytodevelopAKI.Takentogether,these
studiessuggestthatastandardized,objectiveassessmentofdiuretic
responsivenesscanaidinthepredictionofAKIdevelopmentorworsening
severity.
Whendiureticsareunabletoachievefluidandelectrolytehomeostasis,
escalationtotheprovisionofrenalreplacementtherapy(RRT)iswarranted.
DeterminationoftheoptimaltimingofRRTinitiationhasbeenamajorfocusof
studyinthefieldofcriticalcarenephrologywithconflictingoutcomes,35–37but
recentstudiesinthepediatriccardiacsurgerypopulationhaveprovidedsome
positiveresults.However,itisimportanttodispelthenotionthatRRTitself
causesirreversiblekidneydamageandfailure.Nearly20yearsago,onestudy
demonstratedincreasedurineoutputafterperitonealdialysiswasinitiatedin20
infantsaftercardiacsurgery.38Asecondstudyrandomizedpatientstocontinue
versusdiscontinueperitonealdialysis(PD)afterapositivediureticchallenge,
andfoundnodifferencesintotalnegativefluidbalanceorconcentrationsof
novelkidneydamagebiomarkers,andurineoutputcontinuedtoincreaseevenin
thepatientsrandomizedtoPDcontinuation.39
RecentstudieshaveexaminedtheassociationbetweenPDandoutcomesafter
cardiacsurgeryinchildren(Table78.6).Inaretrospectiveanalysis,Bojanand
colleaguesobservedanearly50%decreaseinpatientmortalitywhenPDwas
initiatedonthefirstpostoperativedayversuslaterinthepostoperativecourse.40
TwostudiesbyKwiatkowskiandcolleaguescomparedfluidbalance,mechanical
ventilationdays,andelectrolytemanagementinchildrenwhoreceivedPD
catheterplacementintraoperatively.Ineachofthesestudies,PDcatheterswere
placedintraoperativelybasedonpatientcharacteristicsthatincreasetheriskof
postoperativeAKIdevelopment(Table78.7).21,22Thefirstwasaretrospective
studyofpatientswhoreceivedintraoperativePDcatheterplacementafterthe
institutionofrisk-guidedpracticeversusamatchedhistoricalcohortwhodidnot

receiveacatheterpriortothispractice.PatientswhoreceivedaPDcatheterwere
abletoachievenegativefluidbalanceinthefirst48hoursmoreoften,hadlower
ratesof10%fluidoverload,wereextubated24hoursearlier,andhadfewer
electrolytederangementsthanthosewithoutaPDcatheter.Thesecondstudy
wasaprospectiverandomizedstudyoftheinitiationofPDversusdiureticsin
patientswithurineoutputoflessthan1mL/kgperhourfor4consecutivehours


inthefirst24hoursaftersurgery.PatientswhoreceivedPDwerelesslikelyto
develop10%fluidoverload,andtohaveprolongedmechanicalventilationand
prolongedinotropeuse.GiventhehighincidenceofAKIaftercardiacsurgery,
thesestudiescollectivelysuggestthatPDcathetersshouldbeplaced
intraoperativelyinhigh-riskpatientstopreventseverefluidoverloadandto
maintainelectrolytehomeostasisinpatientswhodevelopoliguriaand/orare
diureticresistant.
Table78.6
OutcomeStudiesofPeritonealDialysis(PD)ProvisioninChildrenAfterPediatricSurgery
Study
(Subjects)
Sorof38(n=
20)
Bojan40(n=
146)
Riley39(n=
20)

Design

Outcomes

Retrospective

UrineoutputincreasesonPD
Nodeaths
Decreased30-and90-daymortalityinearlyPDgroup

Retrospectivecohortstudyof
early(day1)vs.late(>day1)
PD
ProspectiverandomizedtoPD
continuationvs.discontinuation

Kwiatkowski21 Retrospectivematchedcase:
controlofpatientswithvs.
(n=84)
withoutintraoperativePD
catheterplacement
Kwiatkowski22 ProspectiverandomizedPDvs.
furosemide
(n=73)

Urineoutputincreasesinbothgroupsafterrandomization
NodifferencesinurineAKIbiomarkersbetweengroups
afterrandomization
PatientswithaPDcatheter:(1)higherratesofnegativefluid
balance,(2)higherratesofpreventionof10%fluidoverload,
(3)lowerratesofelectrolytedisturbance,(4)extubated24
hoursearlier
PatientsrandomizedtoPD:(1)lesslikelytodevelop10%fluid
overload,(2)lesslikelytohaveprolongedventilatoruse,(3)

shorterinotropeuse,(4)fewerelectrolyteabnormalities

AKI,Acutekidneyinjury.

Table78.7
CriteriaforIntraoperativePeritonealDialysis(PD)CatheterPlacementDuringCardiacSurgeryin
Children
Population
High-riskpatients:PDcatheterplacementplannedpreoperatively

Moderate-riskpatients:PDcatheterplacementconsideredbasedon
clinicalconditionintheoperatingroom

Criteria
Age<3monthsundergoing
bypass
Hearttransplant≤6monthsof
age
Patients≤4monthsundergoing
TOD/DORVrepair
Hearttransplant>6months
Patients>4monthsundergoing
TOD/DORVrepair
Bypasstime>120min


DORV,Double-outletrightventricle;TOF,tetralogyofFallot.

Whenintra-abdominalconditionsexistandpreventtheuseofPD,recent
studieshaveshownpromisewithvariouscontinuousvenovenousdialytic

modalities,eitherwithmachinesthatareadaptedforthispurpose,41orwith
machinesdevelopedspecificallyfortheneonatalpopulation.42,43Useofthese
technologiesrequiresspecializednursingtrainingandprogramdevelopmentto
guidevolumemanagement,aswellasthevariousformsofanticoagulation
neededtopreventcircuitclotting.

Long-TermRenalConsequencesofCardiac
Surgery–AssociatedAKI
TheassociationbetweenAKIandthedevelopmentofCKDhasbeenthesubject
ofincreasedclinicalandbasicstudyoverthelastdecade.44Pediatricsurvivorsof
anAKIepisodeprovideanimportantpopulationforstudyoftheAKItoCKD
interconnection,astheydonotusuallysufferfromthesamecomorbidities,such
asdiabetes,cirrhosis,orchronichypertension,thatleadtoCKDinadults.45
Furthermore,pediatricsurvivorsofcardiacsurgery–associatedAKIprovidea
potentiallymoreinformativegrouptostudy,sincetheyoftenonlysuffertheone
episodeofAKIaroundthetimeofsurgery.Recentstudiesinthepediatric
cardiacsurgerypopulationdoinfactdemonstratetheassociationbetweenAKI
andCKDdevelopment(Table78.8).8,10,46–48Thesestudiesdemonstratea
relativelyhigherprevalenceofmanyCKDfactors,includingdecreased
glomerularfiltrationrate,microalbuminuria,andhypertension.Interestingly,one
studyshowedapersistentelevationinnovelurinarykidneydamagebiomarkers,
suggestingthepresenceofsubclinicalongoingkidneydamage5to7yearsafter
thecardiacsurgery–associatedAKIepisode.Unfortunately,itiswell
documentedthatstandardizedandcomprehensivefollow-upofAKIsurvivors
forCKDdevelopmentisnotcommonpractice.49ThedevelopmentofAKI
providesauniqueopportunitytoestablishsystemstofollowpatientsforearly
signsofCKD,withthepotentialtosloworevenpreventCKDprogression.50,51
Table78.8
Long-TermOutcomesinPediatricSurvivorsofCardiacSurgery–AssociatedAKI
Follow-Up