Comparison of hemodynamic profiles in transurethral resection of prostate vs transurethral resection of urinary bladder tumors during spinal anesthesia: a bioimpedance study

Study Objective: Transurethral resection of prostate (TURP) is more frequently associated with perioperative fluid and electrolyte disturbances than transurethral resection of bladder tumors (TURT) because of irrigating fluid absorption. Because fluid overload may cause hypertension, we compared the patients' intraoperative hemodynamic profiles (including the incidence of hypertension) during TURP vs TURT, both performed during spinal anesthesia, by using the bioimpedance method. Design: Prospective single-blind study. Setting: University hospital. Patients: 80 (40 in each group) men, ASA physical status I and II. Interventions: Patients underwent TURP or TURT surgery with spinal anesthesia. Measurements: Mean arterial pressure, heart rate, cardiac index, and systemic vascular resistance were compared between the 2 groups. A mean arterial pressure greater than 30% from the baseline value was considered as hypertension. Plasma sodium was measured preoperatively, intraoperatively, and postoperatively. Main Results: Transurethral resection of prostate patients received more irrigating fluid (7900 ± 2310 vs 5650 ± 21 560, P < 0.05) and had a higher calculated volume of fluid absorbed: 638 ± 60 vs 303 ± 40 mL for the TURT patients (P < 0.05). Mean arterial pressures were higher with TURP, 30 minutes after the onset of surgery and at the end of the procedure (111 ± 15 vs 100 ± 10 and 109 ± 14 vs 99 ± 14 mmHg, respectively; P < 0.05). However, there was no hypertension in either group. There were no differences in hemodynamic measurements of hyponatremic vs normonatremic patients. Plasma sodium decreased postoperatively more in the TURP group (140.4 ± 2.6 mEq/L baseline to 134.1 ± 3.5 mEq/L, P < 0.05) and was lower postoperatively in the TURP group compared with TURT (134.1 ± 3.5 vs 137.2 ± 2.9 mEq/L, P = 0.04). Conclusions: Although more irrigating fluid was absorbed in the TURP group, there were no episodes of hypertension in either group.