Predictive value of preoperative serum cholinesterase concentration in patients with liver dysfunction undergoing cardiac surgery

Objective There are an increasing number of patients with severe liver dysfunction subjected to open heart surgery. This retrospective study was designed to assess operative results and clarify the degree of liver injury in patients with liver dysfunction undergoing open heart surgery. In addition, determinants influencing their prognosis were assessed. Methods In a 9-year period from 1988 to 1996, we operated on 31 patients with posthepatitis liver dysfunction and 16 with chronic passive congestion of the liver. This group was 2.3% and 1.6% of the 1368 patients undergoing cardiac surgery in the same period. We compared several perioperative factors between survivors and nonsurvivors to determine risk factors affecting mortality. Results In the group with posthepatitis liver dysfunction, the postoperative course of 5 patients among 31 (16.1%) was poor. Serum cholinesterase concentration was lower only in the nonsurvivor group (nonsurvivor vs survivor: 1979 +/- 949 vs 3515 +/- 1424 IU/I, p < 0.05). All patients with cholinesterase < 2000 IU/L died. The duration of CPB (212 +/- 53 vs 150 +/- 54 minutes, p < 0.03) and ACC time (151 +/- 38 vs 96 +/- 40 minutes, p < 0.02) was longer in the nonsurvivor group. In the group with chronic passive congestion, the postoperative course of 5 of 16 (31.3%) patients with valvular disease was poor. Serum cholinesterase concentration was lower only in the nonsurvivor group (nonsurvivor vs survivors: 2006 +/- 435 vs 3483 +/- 1442 IU/L, p < 0.02), and all patients with cholinesterase < 2000 IU/L died. Postoperative bleeding was greater in the nonsurvivor group (3327 +/- 2106 vs 1428 +/- 643 mb, p < 0.05). Multivariate logistic regression analysis including the described pre- and intraoperative factors identified only serum cholinesterase concentration (F = 9.18) as significant. Conclusions A low value of preoperative serum cholinesterase (< 2,000 IU/L) is thought to be the predictor of prognosis after open heart surgery in patients with severe posthepatitis and congestive liver dysfunction. Operative factors (cardiopulmonary time in posthepatitis liver dysfunction and postoperative bleeding in the congestive liver dysfunction) also influenced the prognosis.