RevBrasAnestesiol.2017;67(5):538---540
REVISTA
BRASILEIRA
DE
ANESTESIOLOGIA
PublicaçãoOficialdaSociedadeBrasileiradeAnestesiologiawww.sba.com.br
CLINICAL
INFORMATION
Postpartum
hemorrhage
and
pregnancy
induced
hypertension
during
emergency
lower
segment
cesarean
section:
dexmedetomidine
to
our
rescue
Uma
Hariharan
BhagwanMahavirHospital,RajivGandhiCancerInstituteandResearchCentre,DelhiGovernmentHealthServices, NewDelhi,India
Received6November2014;accepted23December2014 Availableonline1October2015
KEYWORDS
Dexmedetomidine; Obstetricanesthesia; Pregnancy-induced hypertension; Post-partum hemorrhage; Emergencycesarean section
Abstract Dexmedetomidineisahighlyselective␣-2agonistwhichhasrecently
revolution-izedouranesthesiaandintensivecarepractice.Anobstetricpatientpresentedforemergency cesareandeliveryundergeneralanesthesia,withpre-eclampsiaandpostpartumhemorrhage.In carefullyselectedcaseswithrefractoryhypertensionandpostpartumhemorrhage, dexmedeto-midinecanbeusedforimprovingoverallpatientoutcome.Itwasbeneficialincontrollingboth thebloodpressureanduterinebleedingduringcesareansectioninourpatient.
©2015SociedadeBrasileiradeAnestesiologia.PublishedbyElsevierEditoraLtda.Thisisan openaccessarticleundertheCCBY-NC-NDlicense( http://creativecommons.org/licenses/by-nc-nd/4.0/).
PALAVRAS-CHAVE
Dexmedetomidina; Anestesiaobstétrica; Hipertensãoinduzida pelagravidez; Hemorragia pós-parto; Cesarianade emergência
Hemorragiapós-partoehipertensãoinduzidapelagravidezdurantecesarianade emergênciaemsegmentouterinoinferior:dexmedetomidinaparanossoresgate
Resumo Dexmedetomidinaéum␣2-agonistaaltamenteseletivo querecentemente
revolu-cionou a nossa prática de anestesia e tratamento intensivo. Uma paciente obstétrica foi admitida paracesariana deemergência sobanestesia geral,com pré-eclâmpsiae hemorra-giapós-parto.Emcasoscuidadosamenteselecionadoscomhipertensãorefratáriaehemorragia pós-parto,dexmedetomidinapodeserusadaparamelhoraroresultadogeraldapaciente.O fár-macofoibenéficonocontroletantodapressãoarterialquantodosangramentouterinodurante cesarianaemnossapaciente.
©2015SociedadeBrasileiradeAnestesiologia.PublicadoporElsevierEditoraLtda.Este ´eum artigoOpen Accesssobumalicenc¸aCCBY-NC-ND( http://creativecommons.org/licenses/by-nc-nd/4.0/).
E-mail:[email protected]
http://dx.doi.org/10.1016/j.bjane.2014.12.002
Postpartumhemorrhageandpregnancyinducedhypertension 539
Introduction
Eversincedexmedetomidinehasbeenapprovedforhuman use by the FDA in 1999, its indications and ramifications in anesthesia and intensive care has been increasing. Its useinobstetricanesthesiahasbeendelayeddueconcerns regarding maternal and fetal effects. In view of its sev-eral advantageous effects, it has been used in cesarean sections for controlling blood pressure response to intu-bation and as an alternative agent for labor analgesia as an IVPCA (intravenous patient controlled analgesia). We presentacaseofPIHforemergencycesareansectionunder general anesthesia, where dexmedetomidine wasused to controlherrefractoryhypertension,uterotonicity,stabilize hemodynamics,prevention of postoperative shivering and supplementpostoperativeanalgesia.
Case
report
A30yearold,70kg,primigravidapresentedtothe obstet-ric emergency in labor, with uncontrolled blood pressure andnon-reassuring fetalheartrate at 38weeksperiodof gestation.She wasadiagnosedcaseofpregnancyinduced hypertension(PIH)onalpha-methyl-dopatherapy.Shewas postedforemergencycesareansectioninviewofpersistent fetaldecelerations.Thepatientrefusedanykindof neurax-ialblockinviewofpreviousbacksurgeryforlumbarslipped diskandrecurrent back achesince 2years.On preopera-tive evaluation,blood pressure(B.P) was200×102mmHg; pulseratewas120beatsper minute,regular, normal vol-ume;bilateralpedaledema waspresent withnoevidence ofcongestivecardiacfailure.Intravenous(I.V.)Magnesium sulphatetherapy wasstarted preoperativelybythe obste-triciansforseizureprophylaxis.TherewerenosignsofCNS (Central Nervous System) irritation, visual defects, coag-ulopathy or renal dysfunction. Invasive arterial line was institutedpre-inductionforbeat-to-beatpressure monitor-ing. Due to patient refusal, standard general anesthesia withpreoxygenation,rapidsequenceinductionandcricoids pressure was planned after aspiration prophylaxis and appropriatemonitoring.Tominimizehypertensiveresponse tolaryngoscopyandintubation, I.V.preservativefree Lig-nocainehydrochloride2%(2mL)andI.V.Labetololinfusion (5mg.min−1) were given. Modified Cormack and Lehane
gradingwas2B.
Despitealltheabovemeasuresandsingleattemptgentle laryngoscopicintubation,theB.Pwasnotcontrolled.Post intubationB.P.was198×100mmHgandPulserate118min, when O2+ N2O+ Isoflurane inhalational agent werestarted for maintenance of anesthesia. Induction delivery inter-valwas4min.Immediatelyoncordclamping,loadingdose (70g.h−1 over 10min) of dexmedetomidine wasstarted, followed by maintenance dose of 35g.h−1 I.V. infusion (alongwithsyntocinoninfusion).B.Pandpulseratestarted tostabilizeandnormalize.
Deliveryofthebabyandplacentawasfollowedby post-partum hemorrhage (PPH). Despite meticulous attention tohemostasis,syntocinoninfusion,decreasinginhalational anestheticagentandprostadin injection,uterinebleeding wasnot controlled.Dexmedetomidine alsohas uterotonic effects, which was beneficial in controlling this PPH.
Once B.P was controlledand the uterus contractedafter dexmedetomidineinfusion,uterinebleedingwasalso con-trolled.Theapgarscoresofthebabywerenormalatbirth, 1and5min.Afterensuringadequatehemostasis,followed byuterineand skin closure,preparations for reversaland extubationweremade.Dexmedetomidineinfusionwas con-tinued on maintenance dose. On return of spontaneous respiration andtrain-of- fourresponses onneuromuscular monitoring,reversal wasgivenand thepatient extubated whenfullyawake.
Patientmaintainedhervitalswellandherpostoperative B.P was132×80mmHg and pulserate 88beats/min. Pain managementwasdone with multi-modal analgesia (intra-venousparacetamol infusion1g,intramuscular diclofenac injection75mgandincisionsitelocalanestheticinfiltration) alongwithdexmedetomidineinfusion(30mcg.h−1).
Patientwasshiftedtoa highdependency care unitfor observation and monitoring. After 2h, dexmedetomidine infusionwasslowlytapered-offandstoppedafter1h.Inthe meanwhile, her B.P remained within normal limits.After stopping dexmedetomidine infusion, B.P. was controlled withlowdoseintravenouslabetolol(5mgslowI.V.boluses over 1min) asand whenrequired (labetolol wasrequired onlytwice in 24h) andlater withoral amlodepine (10mg twicedailyfromnextday).Thenewbornwasputtobreast feedingwithin4hofbirthandtakencare-offinthenursery. Patient was shifted to ward with normal vitals the next day (after removing arterial line) and later discharged, withoralantihypertensivetherapyandadvisedforregular follow-upwiththeobstetrician.
Discussion
Dexmedetomidine hydrochloride is a highly selective ␣-2 receptor1 agonist (
␣-1 to ␣-2 ratio is 1:1600) with vari-ousapplicationsin anesthesiaandintensivecare. Itisthe S-enantiomer of medetomidine,2 with empirical formula
C13H16N2.
It is given in a loading dose3 of 1
g.kg−1.h−1 over 10min, followed by maintenance intravenous infusion of 0.2---0.7g.kg−1.h−1. It produces4 sedation, sympa-tholysis, cardiovascular stability, anxiolysis, analgesia, neuroprotection and anesthesia-sparing effects. Its pur-portedadvantages5includeminimalrespiratorydepression,
renoprotection, quick offset and cardioprotection. The mainside effectsincludedry mouth, nausea,hypotension and bradycardia. Its reluctant use in obstetrics is due to concerns regarding possible maternal and fetal effects.6
Dexmedetomidineislipophilicanditsplacentalextraction is high. Hence its fetal transfer through the placenta is minimal.Inanimalexperiments,dexmedetomidinehasnot beenfoundtocauseadversefetaleffects.7Ithasbeenused
inobstetricsforcontrolofB.Pduringcesareansectionand forlaboranalgesia.Isolatedcasereportshaveassertedthe safety of dexmedetomidine in obstetric anesthesia.8 Our
540 U.Hariharan
The uterine bleeding got controlled only after starting dexmedetomidineinfusion.PPHisadevastating complica-tionduringdelivery.Wedidnotpreferusingnitroglycerine forB.Pcontrolduetoitsuterinerelaxanteffects.
Inhalational anesthetics could also confound PPH, henceIsoflurane concentration wasdecreased onstarting dexmedetomidine infusion. Once the B.P was controlled withdexmedetomidine, thebleedersalsostopped oozing. Timely control of PPH is this case could be due to the combined effects of B.P control and uterotonicity. This uterotoniceffect of dexmedetomidine needs tobe inves-tigated and researched further. Bloodtransfusion and its attendantcomplicationscouldbeavoidedinpatientswith PPH.Analgesiawasalsosupplementedbydexmedetomidine infusion both intra- and postoperatively. Her hyperten-sion was also under control in the postoperative period. Dexmedetomidine was used only after cord clamping, so the question of fetal effects does not arise in this case, ashighlightedbythenormalapgarscores.Invasivearterial andneuromuscular monitoring was usedalong with other standard monitoring devices in this patient.She also was observedpostoperativelyinan intensivecareunitfor 24h andthentransferredout.
Conclusions
Thoughitistooambitioustoroutinelyrecommendtheuse ofdexmedetomidineinobstetricanesthesia,itsunparalled multipurposeuseinsedation,cardiovascularstability, anal-gesiaandbloodpressurecontrolcannotbeignored.Weneed tobecautiousasthereisapossibilityofmaternal hypoten-sionandfetalbradycardia.
Since its placental extraction is high, its fetal effects areusuallynegligible.Itsplacentalretention ratiois high (Maternal to Fetal Index/Ratio 0.77) and it also directly potentiatestheamplitudeandrateofuterinecontractions. ItsuterotoniceffectandefficacyinPPH,needstobestudied furtherinlargerandomizedtrialsbeforebeingputto tangi-bleclinicaluse.Incarefullyselectedcaseswithrefractory
hypertensionandpost-partumhemorrhage, dexmedetomi-dinecanbeusedforimprovingoverallpatientoutcome.It was beneficialin controllingboth the blood pressure and uterinebleedingduringcesareansection,aswellasfor anal-gesiainourpatient.Suchcasesofpatientrefusalor some relative contraindicationto regionalanesthesia for emer-gencyoperativedeliverymayposeachallengeforthe anaes-thesiologists,especiallywhencomplicatedbyPIHorPPH.
Conflicts
of
interest
Theauthordeclaresnoconflictsofinterest.
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