液体复苏对初进高海拔地区重度失血性休克犬氧合功能的影响

Effect of fluid resuscitation for hemorrhagic shock on oxygenation of subjects in early period of first visit of high altitute area, an experimentation on dogs

目的探讨液体复苏对初进高海拔地区重度失血性休克犬氧合功能的影响。方法13只成年杂种犬由海拔1510m地区用1d时间被运至3780m的高海拔地区，随机分为3组。每只犬麻醉后经颈静脉放置漂浮导管进行氧合功能监测，经股动脉放血使平均动脉压（MAP）维持在（35土5）mmHg（1mmHg-0．133kPa），建立重度失血性休克模型。对照组：制模后不进行液体复苏；乳酸林格液（LR）组：制模后1h输入1．5倍失血量的LR；羟乙基淀粉（HES）组：制模后1h输入等失血量的6‰HES（贺斯）；然后3组模型犬均输以5ml·kg^-1·h^-1LR作为维持量，在不同时间点观察氧合功能的变化。结果对照组犬在制模后2h全部死亡。休克1h，两个液体复苏组氧消耗（VO2）、氧输送（DO2）、氧摄取率（O2ER）、动脉血氧饱和度（SaO2）均较放血前明显降低．而静脉血氧饱和度（SvO2）、肺泡-动脉血氧分压差（A—aDO2）较休克前明显升高（P均〈0．05）。复苏2h，LR组VO2、DO2、O2ER、SaO2均较休克1h显著升高，而A—aDO2则显著降低（P均〈0．05）；HES组VO2、DO2、O2ER均较休克1h显著升高，而SvO2显著降低（P均〈0．05）。结论对初进高海拔地区的重度失血性休克犬如果不进行有效的液体复苏，死亡率达100％；输入1．5倍失血量的LR后2h氧合功能达到了预期的复苏指标；而输入等失血量的6％HES后2h氧合功能没有达到预期的复苏指标。

Objective To investigate the effect of fluid resuscitation on oxygenation of subjects with hemorrhagic shock in early period of first visit to area of high altitute, an experiment in dogs was performed. Methods A model of serious hemorrhagic shock was reproduced by exsanguination resulting in a lowering of mean arterial pressure to （35±5） mm Hg （1 mm Hg=0. 133 kPa） maintain for 1 hour. Thirteen mongrel dogs were carried to an area of 3 780 metres above sea level from an area of 1 510 metres, and they were randomly divided into three groups, namely lactated Ringer＇s （LR） group, 6% hydroxyethyl starch （HES） group, and control group. The dogs in LR group were infused intravenously LR in 1.5 times the volume of blood loss; those in 6% HES group were given HES in equal volume. No fluid infusion was given in the control group. After 1 hour of resuscitation, LR was intravenously given at 5 ml ~ kg t . h i in all groups as maintenance dose. The changes in oxygenation were observed. Results All animals in control group were dead after 2 hours. One hour after establishment of shock, the oxygen consumption （VO2）, oxygen delivery （DO2）, oxygen extraction ratio （O2ER）, arterial oxygen saturation （SaO2） in two resuscitation groups were significantly lower than those before shock, but venous oxygen saturation （SvO2） and alveolar-arterial oxygen difference （A-aDO2） were significantly higher （all P〈0.05）. In LR group, the oxygenation parameters including VO2, DO2, O2ER, SaO2 after 2 hours of resuscitation were significantly higher than those 1 hour after shock, while A-aDO：; was significantly lower （all P〈0. 05）; and in HES group, VO2, DO2, O2ER were significantly higher than those 1 hour after shock, while SvO2 was significantly lower （all P〈0.05）. Conclusion All dogs with serious hemorrhagic shock would die of hemorrhagic shock in the early period of enterring a high ahitute area if fluid resuscitation is denied. Two hours after infusion of LR in 1.5 times of quantity of blood loss, oxygenation can be restored to expected normal values. Infusion of 6% HES with an equal volume of blood loss, oxygenation dose not reach expected level 2 hours after resuscitation.