Perioperative Cumulative Fluid Balance and Its Association with an Increase in Costs after Major Surgery

Positive fluid balance (FB) during the perioperative period may increase the incidence of postoperative complications, which may lead to longer hospitalization and higher hospital costs. However, a definitive association between positive FB and hospital costs has not yet been established. This retrospective observational study examined the association between perioperative FB and hospital costs of patients who underwent major surgical procedures. Medical records of patients who underwent major surgery (surgery time >2 h, estimated blood loss >500 mL) from January 2010 to December 2017 were analyzed to determine the associations between calculated FB (%, total input fluid-output fluid in liter/weight (kg) at admission) and total hospital cost ($). The analysis included medical data of 7010 patients. Multivariable linear regression analyses showed that a 1% increase in FB in postoperative day (POD) 0 (24 h), 0⁻1 (48 h), 0⁻2 (72 h), and 0⁻3 (96 h) significantly increased the total cost by $967.8 (95% confidence interval [CI]: 803.4⁻1132.1), $688.8 (95% CI: 566.3⁻811.2), $591 (95% CI: 485.7⁻696.4), and $434.2 (95% CI: 349.4⁻519.1), respectively (all p < 0.001). Perioperative cumulative FB was positively associated with hospital costs of patients who underwent major surgery.