Hypernatremia is associated with mortality in severe elderly sepsis patients

Objective: To explore the relationship between hypernatremia and 28-day mortality in elderly sepsis patients. Methods: A total of 179 elderly patients (age ≥65 years) with elevated serum sodium admitted to the Department of Critical Care Medicine of Nanjing Hospital affiliated with Nanjing Medical University from September 2021 to September 2022 were included in this retrospective observational study. The clinical data of all patients were collected, and the patients were divided into septic group and nonseptic groups according to the Sepsis 3.0 definition. The clinical features, acute physiological and chronic health II score (APACHE II score), mechanical ventilation time, serum sodium value and duration of serum sodium elevation were compared between the two groups. ROC curves were drawn to evaluate the predictive value of each index on the prognosis of sepsis patients, and Kaplan‒Meier survival analysis was carried out on patients with different serum sodium peaks. Results: (1) The changes in serum sodium within 48 hours after admission in the sepsis group were small and statistically significant compared with those in the nonsepsis group (P = 0.039); however, the serum sodium elevation duration was longer (P = 0.018). (2) Compared with nonseptic patients, the 7-day mortality of septic patients was higher (15.8 vs. 7.7, P