不同止血带压力对血流动力学和代谢及再灌注损伤的影响

Effects of Tourniquet with Different Air Pressure on Haemodynamics and Metabolic Changes and Reperfusion Injury

目的探讨不同压力水平的气压止血带对人体血流动力学和代谢的影响及其导致的再灌注损伤，为临床合理应用止血带提供依据。方法随机选择择期下肢手术、年龄19-65岁的患者40例，随机分为试验组和对照组，止血带压力分别为（上肢基础血压收缩压＋40）mmHg和500mmHg。分别于上止血带前、松止血带前、松止血带后1min、2min、5min及10min抽取股静脉血测定肌酸激酶（CK）、乳酸脱氢酶（LDH）并作血气分析，同时记录各时间点的BP和HR。术中由外科医生评价止血带止血效果。结果两种压力止血带的止血效果相当。松止血带后1min两组MAP即明显低于基础水平，而HR显著增快，P〈0．05。松止血带后1min和2min时CK明显升高，而LDH则在松止血带后2min和5min时有明显升高，P〈0．05。两组pH在松止血带后1min和2min时显著下降，P〈0．05；PCO2则在松止血带后1min显著升高，P〈0．01；PO2在松止血带后1min和2min时亦较基础水平有明显升高，P〈0．05；SvO2则在松止血带后2min开始明显升高，在5min时达最高水平，P〈0．05。但各时间点组间的MAP、HR、CK、LDH和血气分析等各项指标比较无统计学差异，P〉0．05。结论止血带引起肢体缺血所导致的代谢水平变化和再灌注损伤水平与有效的止血带压力大小没有明显的关联性。低压力（SBP＋40mmHg）止血带能取得良好的止血效果，同时并发症少，患者舒适度高。

Objective To study the effect of tourniquet with different air pressure on haemodynamics and metabolic changes and reperfusion injury, and to offer evidence for reasonable application of tourniquet. Methods Forty patients, 19 -65 years old, underwent selective limb surgery, were randomly assigned to two groups： trial group and control group. The air pressure of tourniquet was basal systolic blood pressure （SBP） ＋ 40mmHg and 500mmHg respectively. Creatine kinase （CK）, lactate dehydrogenase （LDH）and femoral vein blood gas were measured before inflation and 1,2,5,10min after deflation of a pneumatic thigh tourniquet. Hemostasis effect was evaluated by surgeons. Results Two kinds of tourniquets had comparable effect. Mean arterial pressure （MAP） decreased at all time points and HR increased at 1,3,5min after tourniquet inflation （P（0. 05）; CK increased significantly at 1,2min and LDH increased significantly at 2,5min after inflation （P〈0. 05）; pH decreased obviously at 1,2min,PCO2 increased significantly only at lmin and PO2 increased at 1,2min after inflation （P〈0. 05） ;SvO2 started to increase at 2min and reached top at 5min after tourniquet release （P 〈0. 05）. There were no statistics difference between two groups on MAP, HR,CK,LDH and blood gas （P〉0. 05）. Conclusion There were no significant relationship between haemodynamics and metabolic changes and reperfusion injury and the air pressure of tourniquet. Tourniquet with low air pressure （SBP ＋ 40mmHg） can efficiently stop bleeding with little complications and high degree of comfort.