Effect of spinal versus general anesthesia on bladder compliance and intraabdominal pressure during transurethral procedures

Study Objective: To evaluate the influence of spinal versus general anesthe sia on bladder compliance and intraabdominal Pressure in elderly males unde rgoing elective transurethral resection of the Prostate Design: Prospective, randomized, open-label study. Setting: Teaching hospital Patients: 21 ASA physical status I, II and III patients at feast 18 years o f age, undergoing transurethral surgery. Interventions: According to a computer-generated randomization schedule, pa tients were allocated to one of two groups. In Group Spinal (S) 10 mg of hy perbaric tetracaine was administered intrathecally. In Group, General Anest hesia (GA) patients received fentanyl intravenous (IV) I to 2 mu g/kg and p ropofol IV 1.0 to 2.0 mg/kg for induction of anesthesia. Thereafter, a lary ngeal mash airway reins inserted and with spontaneous ventilation, anesthes ia was maintained by administering isoflurane (end-tidal 0.7% to 1.2%) and 70% nitrous oxide (N2O) in oxygen. Intraabdominal pressure and bladder comp liance were recorded prior to the induction of anesthesia and immediately b efore the onset of the surgical Procedure. Measurements and Main Results: The two groups were demographically comparab le. In Group S, mean bladder compliance was significantly (p = 0.003) highe r and mean intraabdominal pressure significantly lower (p = 0.007) when com pared to baseline preanesthetic values. In Group GA, mean intraabdominal pr essure significantly (p = 0.006) decreased when compared to baseline preane sthetic recordings. Following the induction of general anesthesia, a small change in bladder compliance was noted. However, statistical significance w as not reached Data were analyzed and compared using Student's t-test (p < 0.05 was considered statistically significant). Conclusion: Both spinal and general anesthesia induced a significant decrea se in intrabdominal pressure. While both techniques were associated with an increase in bladder compliance, statistical significance was demonstrated only in the spinal anesthesia treatment group. (C) 1999 by Elsevier Science Inc.