异丙酚全凭静脉麻醉对犬输液代谢动力学的影响

应用物质守恒定律和容量动力学分析全凭静脉麻醉对犬输液代谢动力学的影响。方法将40只犬按随机数字表法分为4组。清醒输注乳酸钠林格液组(CR组,n=10),30 min内经静脉输注乳酸钠林格液30mL·kg-1;全凭静脉麻醉后输注乳酸钠林格液组(AR组,n=10),全凭静脉麻醉后30min内经静脉输注乳酸钠林格液30mL·kg-1;清醒输注羟乙基啶粉组(CH组,n=10),30min内经静脉输注羟乙基淀粉15mL·kg-1;全凭静脉麻醉后输注羟乙基啶粉组(AH组,n=10),全凭静脉麻醉后30 min内经静脉输注羟乙基淀粉15mL·kg-1。观察4组犬心输出量(CO)、平均动脉压(MAP)、心率(HR)、中心静脉压(CVP)的基础值(T0)、输液开始时(T1)、输液结束时(T2)、输液结束后60min(T3)等情况,以及在实验犬稳定后、开始输液时和以后的每5min经右侧股静脉抽取静脉血1mL,用于测定血红蛋白(Hb)和红细胞压积(Hct),同时记录4组犬总的尿量。应用物质守恒定律和容量动力学理论分析得到以下参数:中央室靶容积(V1)、周围室靶容积(V2)、转移系数(Kt)、清除速率常数(Kr)、容量增加和容量扩张效率。结果 AR组、AH组在T1时HR、MAP、CO值均较T0时低(均P<0.05),CR组、AR组、CH组、AH组犬在T2时CVP、CO值均较T0时高(均P<0.05)。AR组、CH组、AH组犬V、Kr和总尿量均明显低于CR组(均P<0.05),CH组、AH组犬V、Kr值均明显低于AR组(均P<0.05),AR组犬V1、Kr、Kt值较CR组低、V2较CR组高(均P<0.05)。AH组、CH组犬在20、30、35、40、45、50、60min时容量增加值和容量扩展效率均较CR组、AR组高(均P<0.05)。结论全凭静脉麻醉下输注乳酸钠林格液,减少了尿量的排出和目标靶容量,增加了液体在周围间隙的聚集,对输注羟乙基淀粉没有太大的影响,且羟乙基淀粉相对于乳酸钠林格液有更好的扩容效果。

Influence of Total Intravenous Anaesthesia with Propofol on Infusion Metabolism Dynamics in Dogs

Objective To investigate the effect of total intravenous anesthesia on infusion metabolism dynamics in dogs using the law of conservation of matter and volume kinetics.Methods Forty dogs were randomly divided into four groups,with 10 dogs in each group.The CR group was intravenously infused with lactate Ringer’s solution(30 mL·kg-1) within 30 minutes in the awake state.The AR group was given lactate Ringer’s solution(30 mL·kg-1) within 30 minutes after total intravenous anesthesia.The CH group was intravenously infused with hydroxyethyl starch(15 mL·kg-1) within 30 minutes in the awake state.The AH group was given hydroxyethyl starch(15 mL·kg-1) within 30 minutes after total intravenous anesthesia.Cardiac output(CO),mean arterial pressure(MAP),heart rate(HR) and central venous pressure(CVP) were measured before infusion(T0),at the start of infusion(T1),at the end of infusion(T2),and at 60 minutes after the end of infusion(T3).After dogs were stabilized,venous blood(1 mL) was collected from right femoral vein for the determination of hemoglobin(Hb) and hematocrit(Hct) every 5 minutes.In addition,the total urine output was recorded in the four groups.The law of conservation of matter and volume kinetics were used to analyze central room target volume(V1),peripheral room target volume(V2),distribution rate(Kt),elimination rate constant(Kr),volume increase and volume expansion efficiency.Results Compared with T0,the HR,MAP and CO significantly decreased at T1 in AR group and AH group,but the CVP and CO obviously increased at T2 in CR group,AR group,CH group and AH group(all P<0.05).Compared with CR group,the V1,V2,Kr and total urine output significantly decreased in AR group,CH group and AH group(all P<0.05).Compared with AR group,the V1,V2 and Kr significantly decreased in CH group and AH group(all P<0.05).Compared with CR group,the V1,Kr and Kt significantly decreased but V2 obviously increased in AR group(all P<0.05).Compared with CR or AR group,the added capacity and volume expansion efficiency significantly increased in AH group and CH group at 20,30,35,40,45,50 and 60 minutes after the start of infusion(all P<0.05).Conclusion The infusion of lactate Ringer’s solution under total intravenous anesthesia can decrease urine output and target volume and increase the aggregation of the liquid in surrounding space.Total intravenous anesthesia has no effect on the infusion of hydroxyethyl starch.However,hydroxyethyl starch is superior to lactate Ringer’s solution for volume expansion.