Incidence of acute kidney injury after open gynecologic surgery in an enhanced recovery after surgery pathway

Objective: To determine the incidence of postoperative AKI after open gynecologic surgery within ERAS, compare AKI in pre-ERAS and ERAS cohorts, and identify factors associated with AKI. Methods: We compared postoperative AKI in patients who underwent open gynecologic surgery at one institution before and after ERAS implementation. AKI was defined as acute risk, injury, or failure by RIFLE criteria. Pre-ERAS and ERAS cohorts were matched using propensity score analysis in a 1:1 fashion using the nearest neighbor technique. Chi-squared, Fisher's Exact, and Wilcoxon rank-sum tests were used. Results: Among 1334 ERAS and 191 pre-ERAS patients, postoperative AKI incidence was higher in the ERAS cohort (13.1% vs 5.8%, p = .004). In 166 matched pairs, ERAS patients had higher incidence (16.9% vs 5.4%, p < .001) and odds (OR 3.54, 95% CI 1.61–7.76) of AKI. Within ERAS, AKI was associated with older age (median age 65 vs 57, p < .001), Charlson Comorbidity Index score ≥ 3 (71.4% vs 57.9%, p < .001), and higher intraoperative estimated blood loss (400 vs 225 mL, p < .001), fluid administration (net fluid balance +1535 vs 1261 mL, p < .001), and hypotension lasting >5 min (41.7% vs 30.7%, p < .001). ERAS patients with AKI had longer hospital stays (median 4 vs 3 days, p < .001) and more readmissions (19% vs. 10%, p < .001) and grade 3+ complications (26% vs. 7%, p < .001). Conclusions: The incidence and odds of postoperative AKI was higher after gynecologic surgery within ERAS, and patients with AKI were more likely to have complications. Potential strategies to prevent postoperative AKI include perioperative fluid and blood pressure optimization.