血流动力学改变发生止血带充气，持续充气及放气衙（1）充气期：肢体驱血和止血带反气时，回心血量增多，外周血管阻力增加，临床上表现为中心静脉压或动脉压轻微增高。然而当病人有严重的静脉曲张或心室顺应性极差时。脉动压会显著升高。若双侧下肢止血带同时充气，可导致中心静脉压明显增高。
Hemodynamic changes: tourniquet inflation, continuous inflation and deflation (1) inflation period: during limb drive and tourniquet refluxing, the amount of return heart blood increased, peripheral vascular resistance increased, and the clinical manifestations were slight increase of central venous pressure or arterial pressure. However, when the patient has severe varicose veins or poor ventricular compliance. The pulsating pressure will increase significantly. If the tourniquets of both lower limbs are inflated at the same time, the central venous pressure will be significantly increased.
（2）放气期：止血带放松时缺血的肢体发生现灌注，通常会导致中心静脉压和动脉压降低，若血压下降极其明显时可导致心跳骤停，发生因素包括，外周血管阻力突然下降，急性失血以及代谢产物时循环的抑制。
(2) Deflation period: when the tourniquet is relaxed, the ischemic limb will be perfused, which usually leads to the decrease of central venous pressure and arterial pressure. If the blood pressure drops extremely obviously, it can lead to cardiac arrest. The occurrence factors include sudden decrease of peripheral vascular resistance, acute blood loss and circulation inhibition of metabolites.
（3）持续充气期：在全身麻醉时，持续充气河北立体车库 消防报警器塑料配件 电缆接地箱 电缆保护接地箱 塑料土工格栅 消弧线圈装置 15—60分钟可引起高血压，其原因尚不清楚，有人认为这可能反映了肌肉或神经细胞缺血已达到临界水平。有时加深麻醉也不能使血压降低，需加用血管扩张剂旭肼苯哒嗪、哨苯地平、拉贝洛尔等才起效。
(3) Continuous inflation period: during general anesthesia, continuous inflation for 15-60 minutes can cause hypertension. The cause is still unclear. Some people think that this may reflect the critical level of muscle or nerve cell ischemia. Sometimes, the blood pressure can not be reduced by deepening anesthesia, and the vasodilators, such as xuhydrazine, saofendipine and labetalol, are needed to take effect