羟乙基淀粉溶液在复苏肠缺血再灌注休克中的作用

目的　比较不同剂量羟乙基淀粉溶液 ( HES)对兔肠缺血再灌注损伤所致休克的复苏作用。方法　 32只新西兰白兔随机分为 4组 :模型对照、乳酸林格液复苏组 ( L RS,2 0 m l· kg- 1 · h- 1 ) ,小剂量 HES复苏组 ( HES2 ml· kg- 1· h- 1 L RS18m l· kg- 1· h- 1 ) ,大剂量 HES复苏组 ( HES2 0 ml· kg- 1· h- 1 )。采用肠系膜上动脉夹闭 6 0 m in后松夹行再灌注制备肠缺血再灌注休克模型 ,松夹再灌注时同步进行液体复苏。观测各时间点的血流动力学参数 (平均动脉压、心率、心排血量、肠系膜上动脉血流 ) ,并通过测定肠黏膜CO2 分压和动脉血 CO2 分压的差值 (动脉二氧化碳间隙 )、肠黏膜 p H值、动脉血乳酸浓度和氧输送等指标间接评估组织氧合情况。实验结束后累计动物死亡数。结果　 HES能明显提高肠缺血再灌注休克时的血流动力学参数 ,与对照组和 L RS组比较差异均有显著性 ( P均 <0 .0 5 ) ;小剂量 HES比大剂量 HES改善血流动力学参数的作用更平稳 ( P均 <0 .0 5 ) ,且较其他 3组能明显降低血乳酸浓度和动脉二氧化碳间隙 ,减轻 p Hi的降低 ( P均 <0 .0 5 ) ;而大剂量 HES对上述参数的影响不明显 ,并可见动物口鼻出血及死亡 ;小剂量或大剂量HES与其他两组比较均能使氧输送回升 ( P均 <0 .0 5 )。结

Roles of hydroxyethyl starch solution in resuscitation for shock induced by ischemia/reperfusion injury of the intestine

OBJECTIVE: To compare the effects of high and low doses of 6% hydroxyethyl starch solution (HES) on resuscitation for shock induced by ischemia/reperfusion injury of the intestine in rabbits. METHODS: Thirty-two anesthetized rabbits were randomized into four groups of eight animals each. The animals in the control group received no fluid resuscitation, animals in group 2 received lactated Ringer's solution (LRS, 20 ml x kg(-1) x h(-1)), those in group 3 received LRS+HES (LRS 18 ml x kg(-1) x h(1)+HES 2 ml x kg(-1) x h(-1), low dosage of HES), and those in group 4 received HES only in high dosage of HES (20 ml x kg(-1) x h(-1)). All these rabbits underwent intestinal ischemia/reperfusion injury developed by occluding superior mesenteric artery (SMA) with a noncrushing vascular clamp for 60 minutes and then the clamp was loosened for 240 minutes. The fluid resuscitation began at the same time of reperfusion. Hemodynamic parameters including mean artery pressure, heart rate, aortic velocity (as cardiac output), and SMA blood flow were measured. Tissue oxygenation was assessed indirectly by measuring the tonometric parameters of the gut, including difference between partial pressure of carbon dioxide in intestinal intramucosal and partial pressure of carbon dioxide in arterial blood (Pt-aCO(2) gap), intestinal intramucosal pH (pHi), arterial blood lactate acid concentration and oxygen delivery. Mortality of the rabbits was counted at the end of the experiment. RESULTS: Hemodynamic parameters as measured in low and high doses of HES groups were significantly higher in values than LRS group (LRS) and control (all P<0.05). Low dose of HES was better in restoring hemodynamic parameters than high dose of HES (all P<0.05). Low dose of HES could greatly decrease lactate and Pt-aCO(2) gap, significantly improve pHi compared with other three groups (all P<0.05), but high dose of HES did not do so, and oral and nasal bleeding even death of some animals were seen. Low dose and high dose of HES significantly improved oxygen delivery while LRS did not (all P<0.05). CONCLUSION: Low dose of HES together with LRS is more effective than only high dose of HES or LRS in the resuscitation for shock induced by ischemia/reperfusion injury of the intestine in rabbits, resulting in better hemodynamic parameters and tissue oxygenation.