Bailey D R, Miller E D, Kaplan J A, Rogers P W
Anesthesiology. 1975 May;42(5):538-44. doi: 10.1097/00000542-197505000-00006.
Ten consecutive adult patients undergoing elective cardiac surgery with extracorporeal circulation were anesthetized using morphine (1-3 mg/kg) and nitrous oxide. Pre-bypass plasma renin activity showed a 3.5-fold elevation (P smaller than 0.001) over baseline values. This correlated with maximal blood pressure elevation. Plasma renin activity remained elevated during bypass. High baseline aldosterone levels increased 3.4-fold (P smaller than 0.001) after 15 minutes on bypass and 4.0-fold by the end of bypass. Plasma potassium decreased from 3.9 mEq/1 before bypass to 3.2 mEq/1 (P smaller 0.0001) during bypass, and the fractional urinary excretion of potassium was 32 per cent before bypass with a mean of 34.4 per cent during bypass. Urinary output remained high during bypass despite a progressive decrease in glomerular filtration rate. Catecholamine levels showed no significant change. The data suggest that the renin-angiotensin-aldosterone system may play a role in blood pressure regulation during cardiopulmonary bypass and may result in the excessive urinary excretion of potassium and decrease in plasma potassium levels.
连续十名接受体外循环择期心脏手术的成年患者，使用吗啡（1 - 3毫克/千克）和一氧化二氮进行麻醉。体外循环前血浆肾素活性较基线值升高了3.5倍（P小于0.001）。这与血压的最大升高相关。体外循环期间血浆肾素活性持续升高。高基线醛固酮水平在体外循环15分钟后升高了3.4倍（P小于0.001），到体外循环结束时升高了4.0倍。血浆钾在体外循环前为3.9毫当量/升，在体外循环期间降至3.2毫当量/升（P小于0.0001），旁路前尿钾排泄分数为32%，旁路期间平均为34.4%。尽管肾小球滤过率逐渐下降，但体外循环期间尿量仍保持较高水平。儿茶酚胺水平无显著变化。数据表明，肾素 - 血管紧张素 - 醛固酮系统可能在体外循环期间的血压调节中起作用，并可能导致钾的过度尿排泄和血浆钾水平降低。
