THE NON HEMOSTATIC LIABILITIES OF EPSILON-AMINOCAPROIC ACID

Abstract

Introduction. The pandemic use of epsilon-aminocaproic acid (EACA) has the potential to cause intraoperative hyperkalemia [1] and renal dysfunction [2] in the setting of cardiopulmonary bypass (CPB). We hypothesize that EACA causes intraoperative hyperkalemia but the renal impairment in fact lasts into the postoperative period. Therefore we conducted a retrospective investigation into adult cardiopulmonary bypass patients, comparing those who received EACA to those who did not. Methods. This IRB approved, retrospective, chart review evaluated cardiopulmonary bypass records, anesthesia records and laboratory data in 435 consecutive patients requiring cardiopulmonary bypass surgery during July and August 1996 and April and May 1997. (Except for the introduction of epsilon-aminocaproic acid into routine use, there were no other changes in clinical practice, cardiopulmonary bypass technique or personnel.) Data collected:-patient demographics; surgery; surgeon; use of epsilon aminocaproic acid; preoperative and highest serum K during CPB; preoperative, day 2 and highest postoperative serum creatinine; intraoperative urine output; CPB and aortic cross clamp times and volumes of CPB prime and cardioplegia. 160 patients were excluded for incomplete data; use of aprotinin; administration of insulin, furosemide or potassium; aortic cross clamp times <30 minutes or > 120 minutes and cardioplegia over 3 liters. Patients were divided into two groups on the basis of receiving EACA or not. The unpaired t-test and Fishers Exact test were used for statistical comparison between the groups, p< 0.05 significant. Results. EACA was administered to 145 (53%) patients. There were no differences in demographics, preoperative or cardiopulmonary factors between the two groups (Table 1, Table 2). Both groups had significantly increased intraoperative K+ compared to their baseline K+ (p<0.05). However, compared to the No EACA group, those patients who were given EACA had significantly higher serum potassium levels during CPB (range 3.5-6.7 mg/dL) c.f. (range 4.3-7.8 mg/dL), p<0.05. The postoperative serum creatinine in the EACA group was significantly greater than both its baseline value (p<0.05) and the No EACA postoperative creatinine (p<0.05). There was no difference between the preoperative and postoperative serum creatinine in the No EACA group.Table 1Table 2Discussion. Under conditions of this study, EACA administration is associated with intraoperative hyperkalemia and persistent renal dysfunction. We have recently reported that EACA induces subtle changes in intraoperative renal tubular function in cardiac patients [2]. This study demonstrates that the use of intraoperative EACA affects cellular shifts of potassium with subsequent hyperkalemia and influences renal performance leading to postoperative renal impairment.