Hemodynamic Response to Anesthesia in Pregnant and Nonpregnant ICR Mice

摘要

Meanarterialbloodpressure(BP)andheartrate(HR)duringandafterrecoveryfromanesthesiainpregnantandnonpregnantICRmicewereevaluated.Micewereevaluatedduringmechanicalventilation,from15to60minafterinductionofanesthesia.Theanestheticprotocolswerepentobarbital(80mg/kg,givenintraperitoneally[i.p.]);twolowdosesofketamineandxylazine(90mg/kg,7.5mg/kg,respectively,i.p.,withaseconddosegiven20minaftertheinitialdose);andasinglehighdoseofketamineandxylazine(150mg/kg,12.5mg/kg,respectively,i.p.).TheBPwasmeasuredintherightcarotidartery,usingafluid-filledcatheterconnectedtoachambercontainingasolid-statepressuretransducer.Mechanicalventilationwasperformedviatracheotomy,usinganormalizedminuteventilationof3.5ml*minsupxmlns="http://pub2web.metastore.ingenta.coms/"-1/sup*gsupxmlns="http://pub2web.metastore.ingenta.coms/"-1/supfornonpregnantmiceand3.0ml*minsupxmlns="http://pub2web.metastore.ingenta.coms/"-1/sup*gsupxmlns="http://pub2web.metastore.ingenta.coms/"-1/supforpregnantmice.MeanBPwaslowerandHRwashigherinpregnantthaninnonpregnantmiceforeachanestheticprotocol.Pentobarbitalinducedsignificantlygreatertachycardiaandhypotensionthandidtheotherprotocols.TheaverageBPandHRweresimilarbetweentwolowdosesandasinglehighdoseofketamineandxylazine.Duringspontaneousbreathingfrom30to180minafterrecoveryfromanesthesiabyuseofasinglelowdose,ketamineandxylazineinducedsimilarHRprofiles,butmeanBPinpregnantmicerecoveredearlierthandidthatinnonpregnantmice.TheseresultssuggestthatketamineandxylazineinducedadequateanesthesiaforsuperficialsurgicalproceduresinpregnantandnonpregnantmicewhileinducingsmallchangesinHRandBP,andpregnancyresultedinadifferenthemodynamicreactioninresponsetoketamineandxylazine.Thesedatawillbeusefulforthedesignandinterpretationofphysiologicprotocolsusingpregnantandnonpregnantgeneticallytargetedmice.