Hyperosmolar Dehydration in Sepsis: Implications for Initial Fluid Management

OBJECTIVE: Patients with sepsis are prone to hypovolemia which can lead to hyperosmolar dehydration and result in intracellular volume depletion. This study aimed to assess the effect of hyperosmolar dehydration on the clinical outcomes of patients with sepsis and its potential as an indicator of optimal initial fluid management. DESIGN: A nationwide propensity score-matched cohort study analyzing data prospectively collected between September 2019 and December 2021. SETTING: Twenty tertiary- or university-affiliated hospitals in South Korea. PATIENTS: Adult patients with sepsis or septic shock admitted to the ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Hyperosmolar dehydration was defined as serum osmolarity greater than or equal to 295 mOsm/L. The primary outcome, 30-day mortality, was compared using logistic regression adjusted for key prognostic factors in a 1:1 propensity score-matched cohort. Restricted cubic-spline models were used to analyze the clinical outcomes using the pre-ICU fluid volume as a continuous variable. Of the 4,487 patients, 2,605 (58.1%) had hyperosmolar dehydration. After matching, 1,537 pairs were analyzed. The 30-day mortality was higher in the hyperosmolar dehydration group (29.9%) than in the non-dehydration group (27.3%) (adjusted odds ratio, 1.18; 95% CI, 1.00-1.39). Liberal fluid management (greater than30 mL/kg) before ICU admission was associated with improved lactate levels in the hyperosmolar dehydration group ( p = 0.009) without increasing sequential organ failure assessment score ( p = 0.111). Among patients without dehydration, liberal fluid management was associated with an increased Sequential Organ Failure Assessment score ( p = 0.034) and a higher risk for mechanical ventilation ( p < 0.001), and without improving lactate levels ( p = 0.388). CONCLUSIONS: Hyperosmolar dehydration at the diagnosis of sepsis was associated with increased 30-day mortality. A liberal fluid management benefits patients with hyperosmolar dehydration by improving lactate levels without increasing sequential organ failure assessment score. These findings highlight the importance of individualized fluid management based on the dehydration status in sepsis management.