Andersons pediatric cardiology 330
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FocusedNeonatalCare
RespiratoryCare
Althoughpreviouslyrecommended,routineintubationofallneonateswhen
prostaglandinsareadministeredshouldnotbeconsideredtobemandatory,
includingduringtransport,particularlywhentheinfantisundercontinuous
monitoring,and/orthediagnosishasbeenestablishedantenatallyandlowdoses
areprescribed.Thedecisiontointubateshouldbemadebasedontheusual
clinicalindications.Intubationisrecommendedinthepresenceofrespiratory
failure,clinicalsignsofcardiogenicshock,theneedforcardiotropicsupport,
profoundmetabolicorlacticacidosis,gestationalagelessapproximately28
weeks,andanassociateddisorderoftheairways.Oneofthemostchallenging
aspectsofmanagementissupportingthoseneonateswithevolvingchroniclung
diseaseandpulmonaryhypertensionsecondarytopulmonaryvascular
remodeling.Episodicapneaand/orhypoxemiaoccurfrequentlyinthesepatients,
necessitatingtherapeuticintervention.Oxygenisnormallyadministeredto
pretermneonatestomaintainsaturationsgreaterthan70%to75%duetothe
potentialrisksoftissuehypoxiaandadverseneurodevelopmentaloutcomes.329
Theadministrationofprophylacticsurfactanttothosewithanantenatal
diagnosisofaduct-dependentsystemiccirculationisnotwithoutrisk.An
excessivefallinpulmonaryvascularresistancefollowingadministrationof
surfactantmayleadtoexcessiveflowtothelungsattheexpenseofsystemic
perfusion.Thismaybeparticularlyhazardousforneonateswithhypoplasticleft
heartsyndromeandotherductal-dependentlesions,wherethesystemic
circulationmaybetenuous.Clinicalandradiologicconfirmationofrespiratory
distresssyndromeisrecommendedfortheseneonatesbeforeadministering
surfactant.
NeurologicCare
Recentstudiesusingmagneticresonanceimaginghaveidentifiedabnormalities
ofthecerebralwhitematterpreoperativelyinatleasthalffull-termneonates.329
Thereisastrongcorrelationbetweenthesefindingsandprenatal,aswellas
preoperative,arterialtensionsofoxygenandbloodpressure(seealsoChapter
76).Thepresenceofperioperativehyperthermiaorseizures,coexistinggenetic
abnormalities,orassociateddefectsinotherorgansalsoincreasestheriskof
laterneurologicmorbidity.Thepretermneonateisevenmorevulnerabledueto
theeffectsofchronichypoxemiaandintermittentperiodsofsystemic
hypoperfusiononthedevelopingbrain.Infull-termneonates,theseeventsmay
translateintoworselong-termneurodevelopmentaloutcome.Therearelimited
publisheddataonthecombinedimpactofprematurityandacongenital
cardiovascularmalformation.277,330
GastrointestinalCare
Theriskofnecrotizingenterocolitisissignificantlyincreasedintheseneonates,
ofwhomtwo-fifthshadfunctionallyuniventricularphysiology.331Thisismost
likelytoberelatedtointestinalhypoperfusionand/orchronichypoxemia.
Extremeimmaturity,higherdosesofprostaglandin,andepisodiclowcardiac
outputsyndromearealsostrongpredictivefactors.Thesenewbornsrequireda
focusedapproachtonutritionthatbalancestherisksofprematuritywithinthe
contextofafragilecirculation.Whereverpossible,guidelinesshouldbe
developedthatfocusontheuniqueneedsofsuchpretermneonateswithcardiac
disease.Althoughgrowthisparamounttoimproveweight,theyshouldbefed
cautiously.Expressedbreastmilkisrecommended,andfeedsshouldbe
increasedslowlycomparedwiththeirnormalgestationalcounterparts.277,330
Miscellaneous
Theriskofanemiaisprobablyincreasedduetomorefrequentsamplingof
blood.Althoughthethresholdfortransfusioninpretermneonatesremains
unclear,itisprobablyadvisabletoimplementalowerthannormalthreshold.
Thisisparticularlyrelevantforneonateswithfunctionallyuniventricular
physiology,whoareatgreaterriskoftissuehypoxia.Theriskofinfectionis
higherinthesepretermneonates,andvigilanceisrequiredbecauseperiodsof
instabilityareoftenassumedtobecardiovascularinnature.Duetothe
challengesofclinicalassessmentfordysmorphismorgeneticabnormalities,
routinekaryotypicanalysis,togetherwithscreeningfor22qmicrodeletion,is
recommended.
Outcomes
Overallmortalityratesofgreaterthan40%fornewbornsweighinglessthan
1500g,andadoublingofmortalityfornewbornslessthan2.5kg,havebeen
reported.331,332Thesereportsdonottakeintoaccounttheheterogeneityofthe
cardiovascularmalformations.Theliteratureisseverelylackingwithrespectto
long-termoutcomeinthishigh-riskpopulation.Therearereviewson
heterogeneousclustersofpretermneonateswithvaryingtypesofcardiovascular
malformations,butnonethatfocusonanyspecificdefect.Physicianswilluse
thelimitedinformationthatisavailableontheoutcomeformatureinfantswith
certaincardiovascularmalformationsandcombinethiswithdataforcomparable
pretermneonateswhendiscussingprognosis.Follow-updataareurgently
requiredforpretermneonateswithcommoncardiovascularmalformationsso
physicianscanprovideparentswithaccurateinformationonthelikelycourse
andoutcomefortheirchild.
