Effect of change in body weight on clinical outcomes in critically ill patients

Background: Intravenous fluid optimization is an essential component of managing patients in a critical care setting. A cumulative positive fluid balance is consistent with poor outcomes in patients admitted to the intensive care unit (ICU). The overall utility of net cumulative fluid balance as a surrogate for assessing fluid overload has been interrogated. Materials and methods: This study was a prospective single-center observational study, which was done to correlate body weight changes with fluid balance in ICU patients and evaluate its impact on clinical outcomes. Inclusion criteria consisted of adult patients who were admitted to the critical care unit on specialized beds with integrated weighing scales between September 2017 and December 2018. The evaluation of the effect of changes in body weight on ICU survival was the primary objective of the study. Results: We enrolled 105 patients in this study. The ICU mortality was 23.80% with non-survivors showing more weight gain than the survivors. Statistically significant weight gain was documented in the non-survivors on days 3 and 4 (1.9 vs 1.05; p = 0.0084 and 2.6 vs 1.6; p = 0.0030) of ICU admission. Non-survivors had greater cumulative positive fluid balance on fourth, fifth, and sixth days post-ICU admission when compared to survivors (3586 vs 1659 mL, p = 0.0322; 5418 vs 1255 mL, p = 0.0017; and 5430 vs 2305 mL p = 0.0264, respectively). In multivariate regression analysis, cumulative fluid balance did not correlate with days on mechanical ventilation or length of stay in ICU. Changes in body weight and cumulative fluid balance showed a good correlation. Conclusions: In patients admitted to the ICU, weight gain on third and fourth days of admission is concordant with increased ICU mortality. Body weight changes were seen to correlate well with the cumulative fluid balance.