Reiz S, Peter T, Rais O
Acta Anaesthesiol Scand. 1979 Dec;23(6):579-86. doi: 10.1111/j.1399-6576.1979.tb01490.x.
Nineteen patients undergoing abdominal aortic aneurysm surgery were randomly assigned to two groups and investigated to elucidate the mechanisms of declamping hypotension. The control group of nine patients was kept at an average mean pulmonary artery occlusion pressure (MPAOP) of 11 mmHg (1.46 kPa) before declamping. The other group was volume loaded to a MPAOP of 16 mmHg (2.13 kPa) shortly before declamping. Following declamping there was a significantly greater decrease in mean arterial pressure in the control group, with the same reduction of MPAOP in both groups. In parallel, cardiac and stroke volume indices decreased in the control patients, but remained unchanged in the volume-loaded patients. In the control group there was a reduction in myocardial substrate utilization which was not seen in the volume-loaded patients. No signs of myocardial ischemia could be demonstrated in any of the groups. The results indicate that mismatching between intravascular volume and blood volume is the main cause of infrarenal aortic or common iliac artery declamping hypotension. Volume loading before declamping to a slightly elevated MPAOP can effectively prevent hypotension, while a normal MPAOP does not guarantee a stable hemodynamic situation after declamping.
19例接受腹主动脉瘤手术的患者被随机分为两组，以阐明松开阻断钳后低血压的机制。对照组9例患者在松开阻断钳前平均肺动脉闭塞压（MPAOP）维持在11 mmHg（1.46 kPa）。另一组在即将松开阻断钳前通过补液使MPAOP达到16 mmHg（2.13 kPa）。松开阻断钳后，对照组平均动脉压下降幅度显著更大，两组MPAOP下降幅度相同。同时，对照组患者的心输出量指数和每搏输出量指数下降，但补液组患者保持不变。对照组心肌底物利用率降低，而补液组患者未见此现象。两组均未出现心肌缺血迹象。结果表明，血管内容量与血容量不匹配是肾下腹主动脉或髂总动脉松开阻断钳后低血压的主要原因。松开阻断钳前补液使MPAOP轻度升高可有效预防低血压，而正常MPAOP并不能保证松开阻断钳后血流动力学稳定。
