RESUMO
INTRODUCTION: The hydration status is a predictor of survival in critically ill patients. However, it is unclear whether this association depends on the patient clinical condition. This study was designed to analyze the impact of hydration status on survival of critically ill patients with acute kidney injury (AKI) with or without sepsis. METHODS: A prospective cohort study following critically ill patients with AKI consecutively admitted over a one-year period to a teaching hospital intensive care unit (ICU). All patients with AKI stage three or higher of the KDIGO score were included. The hydration status was evaluated through the overhydration (OH) parameter of spectroscopy bioimpedance and sepsis was defined according Sepse-3 criteria. The survival analysis used adjusted competing-risks regression. RESULTS: Forty-eight patients were included, 27 (56%) with a sepsis diagnosis. The main negative predictors of survival among sepsis patients, adjusted by SAPS3 score, were higher OH (SHR 1.1, 95% CI 1.0-1.2, p = 0.02), mechanical ventilation (SHR 6.9, 95% CI 1.0-47.8, p = 0.04) and older age (SHR 1.1, 95% CI 1.0-1.1, p = 0.005). The predictors in non-sepsis patients were lower OH (SHR 0.82, 95% CI 0.71-0.95, p = 0.008) and mechanical ventilation (SHR 12, 95% CI 2.4-6.6, p < 0.001). CONCLUSIONS: This finding suggests that extracellular overhydration is an independent predictor of survival in critically ill patients with sepsis, but it seems to have opposite effect in non-sepsis patients.