Tsuchiya M, Ueda W, Tomoda M, Mokudai Y, Takeda A, Hirakawa M
Department of Anesthesiology, Kochi Medical School, Nankoku.
Masui. 1991 Apr;40(4):540-3.
We measured the hemodynamic and metabolic changes following the release of lower limb tourniquet during halothane anesthesia, and discussed the cause of reduction in the blood pressure and the effective method for prevention. Cardiac index decreased transiently following the release, and gradually increased afterward. Systemic vascular resistance index decreased continuously and progressively until 10 minutes after the release. These results indicate that the causative factors of reduction in the blood pressure are temporary decrease in cardiac output and subsequent decrease in systemic vascular resistance. In mixed venous blood, pH decreased, PCO2 increased and HCO3- remained unchanged after the release. It seems that pH reduction was chiefly caused by the increase in PO2. Thus, the preventive method for reduction in the blood pressure following the tourniquet release may be as follows; 1) intravenous fluid loading, 2) hyperventilation, 3) elevation of lower limb, 4) lightning the anesthesia, and 5) finally giving vasopressors.
我们测量了氟烷麻醉期间下肢止血带松开后的血流动力学和代谢变化，并讨论了血压降低的原因及有效的预防方法。止血带松开后心脏指数短暂下降，随后逐渐升高。全身血管阻力指数持续且逐步下降，直至松开后10分钟。这些结果表明，血压降低的致病因素是心输出量暂时减少以及随后全身血管阻力降低。松开止血带后，混合静脉血的pH值下降、PCO2升高而HCO3-保持不变。似乎pH值降低主要是由PO2升高引起的。因此，止血带松开后预防血压降低的方法如下：1）静脉输液；2）过度通气；3）抬高下肢；4）减轻麻醉；5）最后给予血管升压药。
