The Effects of Hypothermic Hemodilutional Cardiopulmonary Bypass on the Pseudocholinesterase Level

Chae, Byung Kook; Lee, Hye Won; Chang, Seong Ho

Abstract

Pseudocholinesterase is known to be involved in the metabolism of succinylcholine, mivacurium, procaine, chloroprocaine, tetracaine, cocaine, heroin, and other drugs, although the physiologic function has not been well established. Prolonged neuromuscular block following administration of succinylcholine correlates with very low or genetically variant cholinesterase activity. The determination of pseudocholinesterase activity is of importance to the anesthetist in order to predict the susceptibility of the patient to the muscle relaxant, succinylcholine. The purpose of this study was to investigate the change of pseudocholinesterase level during cardiopulmonary bypass(CPB) for open heart surgery with hemodilution and hypothermia. Seven venous blood samples before induction of anesthesia(control), during CPB, and until the fifth postoperative day in 12 patients who underwent open heart surgery were taken. The pseudocholinesterase level was measured by Wako kit and JASCO UVIDEC 77 clinical spectrophotometer. The results were as follows ; 1) The control hematocrit was 40.32+/-6.21% and decreased to 23.72+/-1.86% immediately after the start of CPB(p<0.01) and to 22.42+/-1.93 % 30 minutes after the start of CPB(p<0.01). 2) The control pseudocholinesterase value of 1296.67+/-251.03 IU/L decreased to 915.67+/-228.16 IU/L immediately after the start of CPB(p<0.01), and to 727.83+/-197.58 IU/L 30 minutes after the start of CPB(p<0.01). 3) The mean values of pseudocholinesterase level immediately posteratively, on the first postoperative, and the third postoperative days were 1488.50+/-333.52 IU/L, 1913. 17+614.50 IU/L and 1620.92+/-458.82 IU/L, respectively, and those were significantly increased from the control value(p<0.05, p<0.01, and p<0.01, respectively). 4) The mean value of pseudocholinesterase level on the fifth postoperative day was 1392.25+/-271.69 IU/L, which was not significantly different from the control valule. 5) Transfused units of whole blood, packed red cells, and fresh frozen plasma were 2.8+/-1.4, 3.2 +/-1.0, 3.4+/-0.9, respectively.