Impact of intraoperative fluid restriction on renal outcomes in patients undergoing robotic-assisted laparoscopic prostatectomy.

Robotic-assisted laparoscopic prostatectomy (RALP) requires intraoperative fluid restriction to maintain the optimal view of the operative field during vesicourethral anastomosis and to prevent upper airway edema that may occur due to the steep Trendelenburg position. The aim of this study was to demonstrate that our fluid restriction regimen would not increase postoperative serum creatinine (sCr) levels in patients undergoing RALP. The fluid regimen involved maintaining a crystalloid infusion at 1 ml/kg/h until completion of vesicourethral anastomosis, then rapid infusion of 15 ml/kg within 30 min, followed by maintenance at 1.5 ml/kg/h until post-operative day (POD) 1. The primary outcome of this study was the change in the sCr level from baseline to POD7. Secondary outcomes were the sCr levels on PODs 1 and 2, the surgical view during vesicourethral anastomosis, and the incidences of re-intubation and acute kidney injury (AKI). Sixty-six patients were eligible for the analysis. The paired t test for non-inferiority showed no significant difference in sCr levels between baseline and POD7 (mean ± standard deviation, 0.79 ± 0.14 vs. 0.80 ± 0.18 mg/dl, p < 0.001). Seven patients developed AKI on POD1, but all but one recovered on POD2. Ninety-seven percent of operations were rated as having a good view of the operative field. There were no cases of re-intubation. This study demonstrated that the fluid restriction regimen of 1 ml/kg/h until completion of vesicourethral anastomosis created a good view of the operative field during vesicourethral anastomosis without increasing postoperative sCr levels in patients undergoing RALP. Trial registration: This trial was registered in the University Hospital Medical Information Network under registration number UMIN000018088 (registration date; July 1, 2015).