Association between postoperative fluid balance and mortality and morbidity in critically ill patients with complicated intra-abdominal infections: a retrospective study

BACKGROUND Postoperative fluid overload may increase the risk of developing pulmonary complications and other adverse outcomes. We evaluated the impact of excessive fluid administration on postoperative outcomes in critically ill patients. METHODS We reviewed the medical records of 320 patients admitted to intensive care unit (ICU) after emergency abdominal surgery for complicated intra-abdominal infection (cIAI) between January 2013 and December 2018. The fluid balance data of the patients were reviewed for a maximum of 7 days. The patients were grouped based on average daily fluid balance with a cutoff value of 20 ml/kg/day. Propensity score matching was performed to reduce the underlying differences between the groups. RESULTS Patients with an average daily fluid balance of ≥20 ml/kg/day were associated with higher rates of 30-day mortality (11.8% vs. 2.4%; P=0.036) than those with lower fluid balance (