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) 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