Impact of colloids or crystalloids in renal function assessed by NGAL and KIM-1 after hysterectomy: randomized controlled trial

BACKGROUND: Hydroxyethyl starches are colloids used in fluid therapy that may reduce volume infusion compared with crystalloids, but they can affect renal function in critical care patients. This study aims to assess renal effects of starches using renal biomarkers in the perioperative setting. METHODS: This prospective, controlled, randomized study compared Hydroxyethyl starch 6% (HES) with Ringer's lactate (RL) in hysterectomy. Each episode of mean arterial pressure (MAP) below 60 mmHg guided the fluid replacement protocol. The RL group received 300 mL bolus of RL solution while the HES group received 150 mL of HES solution. All patients received RL (2 mL.kg(−1).h(−1)) intraoperatively to replace insensible losses. Blood and urine samples were collected at three time points (preoperatively, 24 hours, and 40 days postoperatively) to assess urinary NGAL and KIM-1, as primary outcome, and other markers of renal function. RESULTS: Seventy patients were randomized and 60 completed the study. The RL group received a higher crystalloid volume (1,277 ± 812.7 mL vs. 630.4 ± 310.2 mL; p = 0.0002) with a higher fluid balance (780 ± 720 mL vs. 430 ± 440 mL; p = 0.03) and fluid overload (11.7% ± 10.4% vs. 7.0% ± 6.3%; p = 0.04) compared to the HES group. NGAL and KIM-1 did not differ between groups at each time point, however both biomarkers increased 24 hours postoperatively and returned to preoperative levels after 40 days in both groups. CONCLUSION: HES did not increase renal biomarkers following open hysterectomy compared to RL. Moreover, HES provided better hemodynamic parameters using less volume, and reduced postoperative fluid balance and fluid overload.