Fluid management during video-assisted thoracoscopic surgery for lung resection: A randomized, controlled trial of effects on urinary output and postoperative renal function

Background: Increased perioperative fluid administration is an independent risk factor for lung injury after pulmonary resection. In clinical practice, fluid therapy is heavily guided by urinary output; however, diuretic response to plasma volume expansion has been reported to be blunted during anesthesia and surgery. We therefore hypothesized that in patients undergoing video-assisted thoracoscopic surgery, different regimens of intraoperative fluid management would not affect urinary output as would be expected in the nonsurgical scenario. Moreover, a restrictive perioperative fluid approach, as indicated in these operations, will not harm renal function. Methods: One hundred two patients undergoing video-assisted thoracoscopic surgery were randomly allocated to receive intraoperatively either high (8 mL/[kg . h]; n = 51) or low (2 mL/[kg . h]; n = 51) amounts of Ringer's lactate solution. The primary end point was intraoperative urinary output. Secondary end points included postoperative creatinine serum levels and postoperative complication rate. Results: Demographic and surgical data were comparable between groups. Regardless of the intraoperatively fluids administered (mean +/- SD, 2131 +/- 850 vs 1035 +/- 652 mL in high and low groups, respectively; P < .0001), urinary output was similar (median 300 mL). Perioperative creatinine serum levels decreased significantly postoperatively and were not significantly different among the groups. Conclusions: In patients undergoing video-assisted thoracoscopic surgery, intraoperative urinary output and postoperative renal function are not affected by administration of fluids in the range of 2 to 8 mL/(kg . h). The clinical practice of administering fluids to enhance diuresis in the perioperative period should therefore be abandoned.