失血性休克兔容量治疗的合理方案

Evaluation of different factors involved in volume treatment of hypovolemic shock

目的探讨失血性休克兔容量治疗的合理方案。方法采用正交实验设计确立实验因素为输液种类(A)、输液剂量(B)和输液时机(C);实验水平数为三水平,A1、A2、A3分别为6%羟乙基淀粉、生理盐水、林格氏液,B1、B2、B3输液剂量分别为5、10、20 ml/kg,C1、C2、C3分别为休克前、代偿期、失代偿期。应用L9(34)正交表。27只健康新西兰大白兔,经颈内静脉缓慢放血(5-6 ml/min),直至MAP下降30%,建立失血性休克模型。根据正交表顺序进行实验。输液后由颈内静脉注入伊文思蓝,3 h后处死兔。测定肺组织含水率、伊文思蓝含量,并观察肺组织学改变。结果输液种类是影响失血性休克兔肺毛细血管渗漏的主要因素,其次为输液剂量,再次为输液时机。直观分析结果表明最优输液方案为A1B3C2。肺组织病理学结果显示,A1B3C2组肺损伤最轻,其它由轻到重依次为A1B2C2、A3B3C2、A1B3C3、A3B2C1、、A2B2C3、含B1的三组,A2B3C1肺损伤最重。结论失血性休克兔6%HES 20 ml/kg于休克代偿期输入产生效果最好。

Objective To evaluate the three factors-type and volume of fluid and right time for infusion during volume treatment of hypovolemie shock using orthogonal design. Methods Twenty-seven healthy New Zealand white rabbits weighing 2.5-2.8 kg were used. Hypovolemic shock was induced by removing blood from internal jugular vein slowly at 5-6 ml·min^-1 until MAP decreased by 30%. MAP was maintained at this level by removing or reinfusing blood. Hypovolemie shock was divided into 2 stages： compensated stage starting from 0-59 min and deeompensated stage starting from 60 rain. Three factors were evaluated： A type of fluid 6% HES （A1）, normal saline （A2） ,lactated Ringer＇s solution （A3） and; B volume of fluid 5 （B1）, 10 （B2） and 20 （B3） ml·kg^-1 and C right time for infusion, before Bhock （C1） during compensated stage （C2） and decompensated stage （C3） using the orthogonal layout of L9（3^4）. After the fluid was infused 0.5% Evan＇s blue （EB） was injected i.v. Three hours later the animals were killed, The lungs were removed for microscopic examination and determination of lung water [（wet lung-dry lung）/wet lung × 100%] and EB content in the lung by formamide extracting method）. Results The type of fluid was the most important factor among the 3 factors. The order of importance was： type of fluid 〉 volume of fluid 〉 time of infusion, Data analysis indicated that A1 B3 C2 was the best combination of the 3 factors according to the degree of lung injury. Conclusion Adequate amount of HES 200/0.5 infused during compensated stage of hypovolemic shock produces best result.