Larson, David W.

Objective: We aimed to determine a safe zone of intraoperative fluid management associated with the lowest postoperative complication rates without increased acute kidney injury (AKi) risk for elective colorectal surgery patients. Background: To date, standard practice within institutions, let alone national expectations related to fluid administration, are limited. This fact has perpetuated a quality gap. Methods: Elective colorectal surgeries between 2018 and 2020 were included. Unadjusted odds ratios (ORs) for postoperative ileus, prolonged LOS, and AKi were plotted against the rate of intraoperative RL infusion (mL/ kg/h) and total intraoperative volume. Binary logistic regression analysis, including fluid volumes as a confounder, was used to identify risk factors for postoperative complications. Results: A total of 2900 patients were identified. Of them, 503 (17.3%) patients had ileus, 772 (26.6%) patients had prolonged LOS, and 240 (8.3%) patients had AKI. The intraoperative fluid resuscitation rate (mg/kg/h) was less impactful on postoperative ileus, LOS, and AKI than the total amount of intraoperative fluid. A total fluid administration range between 300 mL and 2.7 L was associated with the lowest complication rate. Total intraoperative RL ≥2.7 L was independently associated with a higher risk of ileus (adjusted OR 1.465; 95% confidence interval 1.154–1.858) and prolonged LOS (adjusted OR 1.300; 95% confidence interval 1.047–1.613), but not AKI. Intraoperative RL ≤300 mL was not associated with an increased risk of AKI. Conclusion: Total intraoperative RL ≥2.7 L was independently associated with postoperative ileus and prolonged LOS in elective colorectal surgery patients. A new potential standard for intraoperative fluids will require anesthesia case planning (complexity and duration) to ensure total fluid volume meets this new opportunity to improve care.