Association Between Perioperative Fluid Balance and 30-Day Unplanned Readmission After Major Abdominal Surgery.

Perioperative positive fluid balance (FB) increases postoperative complication and length of hospital stay. We aimed to investigate 30-day unplanned readmission after major abdominal surgery based on perioperative FB (%) on postoperative days (POD) 0 to 3. This retrospective cohort study analyzed medical records of patients who underwent elective major abdominal surgery (surgery time >2 hours, estimated blood loss >500 mL) at a single tertiary academic hospital from January 2010 to December 2017. Cumulative FB was calculated by total input fluid - output fluid in liters × weight (kg)-1 on admission × 100 during POD 0 (24 hours), 0 to 1 (48 hours), 0 to 2 (72 hours), and 0 to 3 (96 hours). Of the 3650 patients in the final analysis, 503 (13.8%) had unplanned readmission within 30 days. In the multivariable logistic regression analysis, FB on POD 0 (24 hours), 0 to 1 (48 hours), 0 to 2 (72 hours), and 0 to 3 (96 hours) showed no significant association with 30-day unplanned readmission (all P > .05). However, an increase of 10 000 points in the total relative value unit scores was associated with 5% increase in 30-day unplanned readmission (odds ratio = 1.05, 95% confidence interval = 1.02-1.07; P = .001), and 1-hour increase in surgery time was associated with 10% increase in 30-day unplanned readmission (odds ratio = 1.10, 95% confidence interval = 1.05-1.15; P < .001). This study showed that perioperative FB is not associated with 30-day unplanned readmission rate after a major abdominal surgery. Total relative value unit scores and duration of surgery were significantly associated with 30-day unplanned readmission rate after major abdominal surgery in a single tertiary academic hospital.