Effect of the volume of fluids administered on intraoperative oliguria in laparoscopic bariatric surgery: a randomized controlled trial.

OBJECTIVE To determine whether intraoperative fluid management affects urine output in patients undergoing laparoscopic bariatric operations. DESIGN Randomized controlled trial. SETTING Academic tertiary referral center. PATIENTS Morbidly obese patients scheduled to undergo laparoscopic bariatric procedures. INTERVENTIONS Patients were randomly assigned to receive intraoperatively high (10 mL/kg/h, n = 55) or low (4 mL/kg/h, n = 52) amounts of Ringer lactate solution. MAIN OUTCOME MEASURES The primary end point was urine output. Secondary end points were postoperative creatinine serum concentration and complication rate. RESULTS Significantly more fluids were administered intraoperatively to patients in the high-volume group compared with the low-volume group (P < .001). Regardless of the amount of fluids administered intraoperatively, low urine outputs (median [range], 100 [15-1050] mL in the high-volume group vs 107 [25-500] mL in the low-volume group; P = .34) were documented and were not significantly different. The mean creatinine serum concentration was within normal range at all times and was not significantly different between the groups (P = .68). The number of patients with complications was nonsignificantly lower in the low-volume group compared with the high-volume group (7 vs 10 patients, respectively; P = .60). CONCLUSIONS In patients undergoing laparoscopic bariatric surgery, intraoperative urine output is low regardless of the use of relatively high-volume fluid therapy. The results suggest that we should reconsider the common practice to administer intraoperative fluids in response to low urine output. Further studies are required to evaluate these data in other surgical patient populations. Trial Registration  clinicaltrials.gov Identifier: NCT00753402.