Abstract
Background Fluid management is important for ensuring hemodynamic stability in critically ill patients but easily leads to fluid overload. However, the optimal fluid balance plot or range for critically ill patients is unknown. This study aimed to explore the dose-response relationship between fluid overload (FO) and hospital mortality in critically ill patients.Methods Data were derived from the China Critical Care Sepsis Trial (CCCST). Patients with sequential fluid data for the first 3 days of admission to the ICU were included. FO was expressed as the ratio of the cumulative fluid balance (L) and initial body weight (kg) at ICU admission as a percentage. Maximum fluid overload (MFO) was defined as the peak FO value during the first 3 days of ICU admission. We used logistic regression models with restricted cubic splines to assess the relationship between MFO and the risk of hospital mortality.ResultsIn total, 3850 patients were included, 929 (24.1%) of whom died in hospital. For each 1% L/kg increase in the FO, the risk of hospital mortality increased by 4% (HR 1.04, 95% CI 1.03 - 1.05, P < 0.001). FO greater than 10% was associated with a 44% increased HR of hospital mortality compared with FO less than 5% (HR 1.44, 95% CI 1.27 - 1.67). Notably, we also found a non-linear dose-response association between MFO and hospital mortality.Conclusions Both higher and lower fluid balance were associated with an increased risk of hospital mortality. Further studies should explore this relationship and seek for the optimal fluid management strategies for critically ill patients.
