七氟醚对犬血流动力学影响的实验研究

Experimentalstudyoftheeffectofsevofluraneonhemodynamicsindogs

选用成年杂种犬１１只，应用Ｓｗａｎ－Ｇａｎｚ漂浮导管，热稀释法测定心输出量，观察０．５、１．０、１．５ＭＡＣ七氟醚对体循环和肺循环血流动力学的影响。结果表明：心率随吸入浓度增加呈下降趋势；平均动脉压及左室泵血功能指标均呈剂量相关性下降；不同浓度间体循环血管阻力无显著性差异；同基础值相比，肺动脉压下降，但与吸入浓度增加无关，１．５ＭＡＣ时肺循环血管阻力增加４０％（Ｐ＜０．０５）。结果提示：七氟醚呈剂量相关性抑制循环功能，其引起动脉压下降主要是抑制心肌收缩力的结果；七氟醚对肺循环影响轻微。

Inordertoassesstheefectofsevoflurane(Sevo)onhemodynamics,elevenhealthydogsactedasthesubjectsinthisstudy.Folowinganestheticinductionwiththiopental(15mg/kg)andtra-chealintubation,0.2%succinycholinewasinfusedformaintenanceofmuscularrelaxation.Theanesthet-icandCO2concentrationswerecontinuouslymonitoredusinganinfraredanalyzer.A5-FSwan-Ganzcatheterwasinsertedviatherightfemoralveinformonitoringpressureandcardiacoutputusingther-modilutiontechniques.Withtheanimalinaquietstateforatleast15hours,succinycholineinfusionwasdiscontinuedandthebaselinewasmeasmed.The0.5,1.0,1.5MACofSevowasgiveninarandomizedconcentrationorder.Alvaribleswererecordedaftera30minequilibrationateachconcentration.Sevoresultedinbradycardia,adose-dependentdecreaseinfemoralarterypressure,cardiacoutput,leftven-tricularstrokeworkindexandrate-pressureproduct.Therewerenosignificantdiferencesinsystemicvascularresistanceamongthethreeconcentrations.Comparedwiththebaselines,meanpulmonaryarterypressuredecreasedby26%,26%and28%(P<0.01),respectively;however,pulmonaryvascularresistanceincreasedby40%(P<0.05)at1.5MACconcentration.Theresultsdemonstratethatthede-pressedefectsonhemodynamicsofSevoareassociatedwithinhaledconcentrationsandthedecreaseofarterypressureismainlyresultedfromdepessionofmyocardialcontractibility.