Postoperative decline in plasma aspirin-esterase and cholinesterase activity in surgical patients.

We studied preoperative and postoperative plasma hydrolysis of aspirin and plasma cholinesterase activity in surgical patients. Postoperative aspirin esterase and cholinesterase activities fell sharply (119 +/- 32 micrograms ml h-1 and 3746 +/- 1068 U l-1 respectively; P < 0.01) in comparison to basal preoperative values (157 +/- 33 micrograms ml h-1 and 4620 +/- 940 U l-1 respectively, P < 0.01). We suggest that alterations in plasma esterase during the postoperative period may be related to the metabolic response to anesthesia- and surgery-induced stress.