选择性外周神经给乳化异氟醚山羊模型的建立

目的 建立选择性山羊外周神经给乳化异氟醚模型,探索外周神经在异氟醚制动中的作用.方法 18只健康成年山羊随机平分为股动脉给乳化异氟醚组(动脉组),股动脉给脂肪乳组(动脉对照组,脂肪乳为乳化异氟醚溶剂)和耳静脉给乳化异氟醚组(静脉组).采用自身上下法,分别钳夹给药侧后肢悬蹄(动脉组,动脉对照组),后肢悬蹄(静脉组)作为伤害性刺激,测定异氟醚最低血液有效分压(minimum partial pressure, MPP).比较3组山羊不同MPP(根据取血部位不同,MPP分为颈静脉MPP、给药侧股静脉MPP和对照侧股静脉MPP).结果 在动脉对照组,血液中没有发现异氟醚,山羊对钳夹刺激具有正常的逃避反应.在动脉组和静脉组,对照侧股静脉MPP与颈静脉MPP比较差异均没有统计学意义.动脉组山羊给药侧股静脉MPP约为颈静脉MPP的7倍(38.45±17.01) mmHg vs. (5.82±2.32) mmHg,1 mmHg=0.1333 kPa, P＜0.05],约为静脉组山羊颈静脉MPP的4倍(9.41±1.61 ) mmHg, P＜0.05].颈静脉MPP动脉组山羊约为静脉组山羊的0.6倍(P＜0.05).结论 成功建立选择性山羊外周神经给乳化异氟醚模型,并提示高分压异氟醚(4倍临床麻醉深度)有外周神经阻滞作用.

Preferential Delivery of Emulsified Isoflurane to Peripheral Nerves in Goats

Objective To develop a new model for preferential delivery of isoflurane to peripheral nerves in goats, and to identify preliminarily volatile anesthetic action sites.Methods Eighteen goats were randomly and equally divided into arterial group, control group and venous group.In the arterial group, emulsified isoflurane was infused into the femoral artery of the goats to deliver isoflurane to the peripheral nerves.In the control group, 30% Intralipid~((R) which used as a solvent of emulsified isoflurane was infused via the femoral artery of the goats with the same infusing speed as that of the arterial group.In the venous group, emulsified isoflurane was infused via an ear peripheral vein.Minimum partial pressure (MPP), the partial pressure (P_(iso)) of isoflurane in blood producing immobility in 50% of the goats exposed to noxious stimuli, was determined with an up-and-down method and a noxious stimulus by clamping the dew-claw of the hindlimbs of the goats in the arterial group and the control group, or the dew-claw of the hindlimb of the goats in the venous group.Results No isoflurane was found in the jugular and femoral veins of the goats in the control group, and normal nociceptive reflexeswere maintained.The MPP of the femoral vein of the goats from the control group did not differ from the MPP of the jugular vein of the goats from the arterial and venous groups.The MPP of femoral vein p was 7 times of that of jugular vein (38.45±17.01) mmHg vs.(5.82±2.32) mmHg, 1 mmHg=0.1333 kPa, P<0.05] in the goats from the arterial group, and 4 times of that of jugular vein in the goats from the venous group (9.41±1.61) mmHg, P<0.05].The MPP of jugular vein in the goats from the arterial group was about half of that of the goats in the venous group.Conclusion A new model of preferential delivery of isoflurane to the peripheral nerves in goats has been developed.Only P_(iso) higher than that used in clinical anesthetic range has a significant anesthetic effect on peripheral nerves.