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InternationalJournalofSurgeryCaseReports41(2017)30–32ContentslistsavailableatScienceDirect
International
Journal
of
Surgery
Case
Reports
jo u r n al ho me p a g e :w w w . c a s e r e p o r t s . c o m
Dynamic
right
ventricular
outflow
obstruction:
A
rare
cause
of
hypotension
during
anestesia
induction
Maria
Enrica
Antoniucci
a,∗,
Christian
Colizzi
b,
Gabriella
Arlotta
a,
Maria
Calabrese
a,
Michele
Corrado
a,
Sergio
Guarneri
a,
Lorenzo
Martinelli
a,
Andrea
Scapigliati
a,
Roberto
Zamparelli
a,
Franco
Cavaliere
aaDepartmentofCardiovascularSciences,InstituteofAnesthesiaandIntensiveCare,CatholicUniversityoftheSacredHeart,L.goGemelli1,00168Rome, Italy
bDepartmentofCardiovascularSciences,InstituteofCardiology,CatholicUniversityoftheSacredHeart,L.goGemelli1,00168Rome,Italy
a
r
t
i
c
l
e
i
n
f
o
Articlehistory: Received14July2017
Receivedinrevisedform11August2017 Accepted11August2017
Availableonline5October2017 Keywords:
Rightventricleoutflowtract Dynamicobstruction
Surgicalcoronaryrevascularization Transesophagealechocardiogram Arterialhypotension
a
b
s
t
r
a
c
t
INTRODUCTION:Dynamicobstructionofrightventricleoutflowtract(RVOTO)isarareconditionthat mayacutelycausesevereheartfailure.Ithasbeenreportedinsomehypertrophiccardiomyopathies, afterlungtransplantation,andinsomecasesofhemodynamicinstabilityaftercardiopulmonarybypass. PRESENTATIONOFCASE:Wereportthecaseofa71-year-oldmanwhodevelopedseverehypotension duringtheinductionofgeneralanesthesiaforsurgicalcoronaryrevascularization.Hypotensiondidnot respondtotheinitialtreatmentwithvasoconstrictorsandfluids.RVOTOwassuspectedduringpulmonary arterycatheterizationbecauseofthedifficultyofthecathetertiptomovefromtherightventricletothe pulmonaryarteryand,successively,becauseofthefindingofalargegradientbetweenthesystolic pres-sureintherightventricleandinthepulmonaryartery.Thediagnosiswasconfirmedbytransesophageal echocardiogram(TEE).Hemodynamicsrecoveredaftertheinfusionofcristalloids,1L,andthesuspension ofvasoconstrictorsandinotropes.
DISCUSSION:ThisisthefirstcaseinwhichRVOTOwasobservedduringtheinductionofgeneral anesthe-sia.Althoughthisisararecondition,thediagnosticsuspectisofoutmostimportancebecausetreatment ismainlybasedonfluidadministration,anddrugswithpositiveinotropicproperties(likemost vasocon-strictors)arecontraindicated.
CONCLUSIONS:RVOTOisanunusual,butpossiblecauseofseverearterialhypotensionduringgeneral anesthesiainduction.TEEisusefulfortheevaluationofseverelyhypotensivepatientswhodonotrespond toroutinetreatmentwithfluidsandvasoconstrictors.
©2017PublishedbyElsevierLtdonbehalfofIJSPublishingGroupLtd.Thisisanopenaccessarticle undertheCCBY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction
Inpatientsaffectedbyheartdiseases,severearterial hypoten-sionthatoccursduringtheinductionofgeneralanesthesiaisoften treatedwithsympathomimeticaminesornorepinephrinetoavoid fluid loading[1,2]. However,these drugs arecontraindicated if hypotension is caused bythe dynamic obstructionof ventricu-lar outflowtractbecause betaadrenergic stimulation increases theobstacleduetomyocardialthickening.Unfortunately,dynamic obstructionisnoteasilyidentifiedintheacutesettingandthe cor-recttreatmentbasedonfluidadministrationiscarriedoutonthe basisofahighdegreeofclinicalsuspicion.Theobstructionofthe
Abbreviations:RVOTO,rightventricleoutflowdynamicobstruction;RVOT,right ventricleoutflowtract;TEE,transesophagealechocardiogram.
∗ Correspondingauthorat:viaArmandodiTullio11,00136Rome,Italy. E-mailaddress:enricaantoniucci@yahoo.it(M.E.Antoniucci).
leftventricleoutflowtractisnotunusualinpatientsaffectedby severemyocardialhypertrophyandsystolicanteriormotionofthe mitralvalve,andisusuallyanticipatedbypreoperative echocardio-graphicfindings.Conversely,thedynamicobstructionoftheright ventricularoutflow(RVOTO)hasonlybeenreportedduring wean-ingfromcardiopulmonarybypassandisexclusivelyanticipatedby rightventriclehypertrophyassociatedwithsomecongenital car-diopathies.WereportthecaseofapatientwhodevelopedRVOTO duringgeneralanesthesiainductionforsurgicalcoronary revascu-larization.ThecasehasbeenreportedinlinewiththeSCAREcriteria
[3].
2. Presentationofcase
ACaucasian71-year-oldmanwasadmittedtothehospitalfor anginaattacksthatoccurredatrest.Hismedicalhistorywas pos-itiveforsmoking,arterialhypertension,pulmonaryemphysema, https://doi.org/10.1016/j.ijscr.2017.08.069
2210-2612/©2017PublishedbyElsevierLtdonbehalfofIJSPublishingGroupLtd.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http://creativecommons. org/licenses/by-nc-nd/4.0/).
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M.E.Antoniuccietal./InternationalJournalofSurgeryCaseReports41(2017)30–32 31
and obstructive sleep apnea syndrome. Hishome therapy was
aspirinandabetablocker.
Coronaryangiographyunveiledthepresenceofcoronaryartery
diseasethataffectedtheleftanteriordescendingartery,theleft
cir-cumflexartery,andtherightcoronaryartery,aswellasthedistal
partoftheleftmaincoronaryartery.Atransthoracic
echocardio-gram(TTE)showedahypertrophicleftventriclewithgoodsystolic
function(leftventricleejectionfraction75%)andmoderate
dias-tolicdysfunction;therightventriclewasnormal.Consequently,
surgicalcoronaryrevascularizationwasplanned.
Onehourbeforetheadmissiontotheoperatingtheatre,the
patient received diazepam,6mg PO, morphine, 10mg IM, and
scopolamine,0.25mgIM.Afewminutesafterarriving,hereported
aprecordialpainandwasgivennitroglycerinoralspray.Acatheter
intheleftradialarteryandavenousperipheral14Gcannulawere
quicklyinsertedbytheanesthetistinchargeandgeneral
anesthe-siawasinducedwithPropofolbyslow IVinjection. Assoonas
80mg ofthedrugwereinjected,thepatientlostconsciousness
anddeveloped severearterialhypotension (systolicblood
pres-sure60mmHg),which wasresistant to saline250mL,calcium
chloride,1gIV,ephedrinechloridetoafinaldosageof50mgIV,
anddopamine300mcgIV.Afterobtainingmusclerelaxationwith
cisatracurium,20mgIV,atracheal tubewaspositionedandthe
patientwas connectedto a mechanical ventilator incontrolled
volumemodality,with10breaths/min,atidalvolumeof560mL,
zeroend-expiratorypressure(ZEEP),andaninspiredO2 fraction
of1.Meanwhile,systolicbloodpressurepartlyrecoveredtoabout
90mmHg.Acentralvenouslineandanintroducerwerepositioned
intheinternaljugularveinandapulmonaryarterycatheterwas
subsequentlyintroducedintotherightventricle,butapparentlydid
notproceedinthepulmonaryarteryinspiteofrepeatedattempts.
Finally,themorphologyofthediastolicpartofthecurve(whichwas
descending)suggestedthatthecatheterwascorrectlypositioned
inthepulmonaryarteryand agradient of45mmHg was
regis-teredbetweensystolicpressurevaluesintheventricle(higher)and
inthepulmonaryartery(lower).Thegradientwascalculatedas
thedifferencebetweenpeaksystolicrightventricularpressureand
peaksystolicpulmonaryarterypressuredirectlyfromthemonitor
values.
Inthemeantime,acardiologistoftheteamperformeda
trans-esophagealechocardiogram(TEE)(PHILIPS,iE33),whichshoweda
hyperkinetic,smallsizedleftventricleandpointedoutthepresence
ofaseveredynamicobstructionoftherightventricleoutflowtract
withendsystolicobliterationoftheoutflowtractandthepresence
ofevidentaliasingasaresultofbloodaccelerationatcolorDoppler
mode(seeFig.1).Itwasimpossibletomeasurebloodspeedfor non-alignment.
Ringerlactate,1000mL,wasrapidlyinfusedandsystolicblood pressureroseto120mmHg;atthefirsthemodynamicassessment withthermodilution,thecardiacindexwas2.3L/min/m2.Thepeak
pressuregradientbetweentherightventricleandthepulmonary artery was assessed again and was 22mmHg. The subsequent coursewasuneventful.Thepatientreceiveda triplebypass(the leftinternalmammaryarterytotheleftanteriordescendingartery andtwosaphenousveinbypassgraftstotheleftmarginalartery andtotheposteriorintraventricularartery).Attheendofthe pro-cedure,hewastransferredtotheCardiacSurgicalIntensiveCare Unit.Afterwards,hewasmovedtothecardiacsurgicalwardinthe 4thpostoperativedayanddischargedfromthehospitalinthe8th postoperativeday.
3. Discussion
DynamicRVOTOhasbeenfirstdescribedinsomehypertrophic cardiomyopathies[4]andafterlung transplantation[5];
succes-Fig.1. Mid-esophagealshortaxisviewshowingseveredynamicobstructionofthe rightventricleoutflowtract.AtcolorDopplermode,end-systolicobstructionis pointedoutbyswan-neckedobliteration(a)andevidentaliasing(b).
Arightatrium;Vventricle;TVtricuspidvalve;AVaorticvalve.
sively,anincidenceof 1–4%hasbeenreportedinpatientswho developedhemodynamicinstabilityaftercardiopulmonarybypass (CPB)[6].Toourknowledge,RVOTOhasneverbeendescribedasa causeofhemodynamicinstabilityduringanesthesiainduction.
DynamicRVOTOmayoriginatefromthehighersusceptibilityof theinfundibulumtoinotropicagents,perhapsasamechanismto protectthepulmonaryvasculaturefromhighpressure[7,8].Itmay causeanacuteheartfailureandrepresentsachallengingdiagnosis. Echocardiographyisneededtoexcludethepresenceofothercauses ofarterialhypotension andtohighlightRVOTOanditsdynamic nature.Thetypicalfindingistheend-systolicobliterationofthe rightventricularoutflowtract,withevidenceofaliasing.A diagnos-ticcriterionisthepresenceofapeakpressuregradientgreaterthan 25mmHgbetweentherightventriclecavitybeforetheobstruction andthepulmonaryartery.Aroughestimateofthegradientmay beperformedwithechocardiogrambyDopplerfunction,butits preciseassessmentrequiresrightheartcatheterization.Acorrect diagnosisisessentialforacorrecttherapythatisbasedonfluid administration,decreasingheartrate,andmaintainingor restor-inganeffectiveatrialcontractiontoimproverightventriclefilling. Drugsthathaveinotropicpropertiesarecontraindicated.
Inthecasereported,RVOTOoccurredafterthearterial vasodila-tioninducedbyanesthetics;successively,inotropedrugsmayhave worsenedtheobstruction.Assoonasthecorrectdiagnosiswas made,preloadoptimizationandinotropicagentswithdrawalwere successfulinrestoringadequatehemodynamics.Thisisthefirst reportofRVOTOduringgeneralanesthesiainduction.The diagno-siswasmadebyTEEandpulmonarycatheterization;innoncardiac surgery,theoccurrence ofthisconditionmayeasilygo undiag-nosed.
4. Conclusions
• Toourknowledge,thisisthefirstcasereportaboutRVOTOthat occursduringgeneralanesthesiainduction.
• RVOTO is an unusual, but possible cause of severe arterial hypotensionduringgeneralanesthesiainduction.
• InabsenceofPACmonitoring,TEEisausefultoolforthe eval-uationofseverelyhypotensivepatientswhodonotrespondto routinetreatmentwithfluidsandvasoconstrictors.
Conflicofinterest
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32 M.E.Antoniuccietal./InternationalJournalofSurgeryCaseReports41(2017)30–32
Funding
Thiscasedidnotreceiveanyspecificgrantfromfunding
agen-ciesinthepublic,commercial,ornot-for-profitsectors.
Ethicalapproval
Notethicalapprovalrequired.
Consent
Awrittenconsentbythepatientcouldnotbeobtainedbecause
theauthorswerenotabletocontacthim.Therefore,anypersonal
detailhasbeenremovedfromthemanuscript andthefigureto
protectanonymity.
Authorcontribution
MariaEnricaAntoniucci:writingthearticle,echocardiographic
imagereview.
ChristianColizziwritingthearticle,echocardiographicimage.
GabriellaArlottadatacollection.
MariaCalabreseliteratureresearch.
MicheleCorradoliteraturereview.
SergioGuarneriliteraturereview.
LorenzoMartinelliechocardiographicimagereview.
AndreaScapigliatidatacollection.
RobertoZamparellidatacollection.
FrancoCavaliereReviewoffinalmanuscript.
Guarantor
FrancoCavaliere.
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