The effect of low-dose acetylsalicylic acid on bleeding after transurethral prostatectomy--a prospective, randomized, double-blind, placebo-controlled study.

Objective: An increase in the loss of blood after ingestion of acetylsalicylic acid (ASA) has been reported after several types of surgery, but randomized placebo-controlled studies have exclusively been performed after coronary artery bypass surgery. The reported effects of ASA on bleeding after transurethral prostatectomy (TURP) have been conflicting. We have studied the effect of low doses of ASA (150 mg) on bleeding after TURP in a prospective, randomized, double-blind, placebo-controlled trial.

Patients And Methods: Patients were randomized to receive either 150 mg ASA (n = 26) or placebo (n = 27) 10 days before surgery. The weight of resected tissue, operation time and blood loss, transfusion requirements and complications were recorded.

Results: There was no significant difference in the median operative blood loss between the groups (p = 0.528), but postoperatively the blood loss in the ASA group (median 284; quartiles 196-660 ml) was significantly higher than in the placebo group (median 144; quartiles 75-379 ml), (p = 0.011). No significant difference was observed between the groups regarding the amount of resected tissue (p = 0.209) or the operating time (p = 0.297). In both groups the operative blood loss was significantly related to the amount of resected tissue (p < 0.005) and the operating time (p < 0.005). No significant difference in transfusion requirements (p = 0.280), time to catheter removal (p = 0.455) and hospital stay (p = 0.820) were observed between the groups.

Conclusion: Long-term low-dose ASA therapy is associated with a significant increase in the postoperative blood loss after TURP, and although no significant difference in transfusion requirements was observed more units of blood were used in the ASA group. We advise that ASA therapy should be withdrawn 10 days before TURP.