Prophylactic Administration of Alpha Blocker for the Prevention of Urinary Retention in Males Undergoing Inguinal Hernia Repair Under Spinal Anesthesia: Interim Analysis of a Randomized Controlled Trial

Introduction: This randomized controlled study aims to investigate the prophylactic effect of tamsulosin on the development of postoperative urinary retention (POUR) in men undergoing elective open inguinal hernia (IH) repair under spinal anesthesia. The study also focused on potentially predisposing factors for POUR. Methods: 100 eligible patients were randomized into two groups. Patients in the experimental group were given two doses of tamsulosin 0.4 mg orally 24 hours and 6 hours before surgery. In the control group, two doses of placebo were administered, in the same manner as the study group. The following parameters were also recorded: the International Prostate Symptom Score (IPSS) questionnaire scores, the presence of scrotal hernia, operation duration, perioperative administration of IV opioids and/or atropine, postoperative pain, and preoperative anxiety. Results: Overall, the incidence of POUR was 37% (37/100) with no difference between the two groups. Among patients receiving tamsulosin, 39.2% (20/51) developed POUR, compared to 34.7% (17/49) in the control group. Preoperative patients’ high anxiety visual analog scale (VAS) score (>51mm) (P=0.007) and the intraoperative use of atropine (P=0.02) were detected as risk factors for POUR. Conclusion: This interim analysis of our prospective randomized trial showed no benefit from the prophylactic use of tamsulosin in preventing POUR after IH repair under spinal anesthesia. This type of anesthesia was also correlated with an overall high incidence of POUR. Preoperative anxiety and administration of atropine were identified as statistically significant factors for POUR. In patients with preoperative high anxiety, VAS score a different type of anesthesia may be used.