The association between serum sodium variation during Pediatric Intensive Care Unit admission and the risk of clinical outcomes in critically ill children: a retrospective cohort study

Abstract This study evaluates sodium variation during Pediatric Intensive Care Unit (PICU) admission and its association with prolonged PICU stay (≥7days) and PICU mortality. Data from 966 critically ill pediatrics (2019-2022) with at least two sodium values available during their PICU admission were analyzed. Patients were categorized based on all recorded sodium values into normonatremia, hyponatremia, hypernatremia, and mixed dysnatremia. The difference between the highest and lowest sodium values during PICU admission was used to identify sodium fluctuation. The statistical method used was Logistic regression model. During the PICU admission, 542 patients developed dysnatremia. The PICU-acquired dysnatremia was independently associated with higher prolonged PICU stay odds after controlling for major confounders. The PICU-acquired hypernatremia (OR:5.23;95%CI:1.72-15.92) and mixed dysnatremia (OR:2.89;95%CI:1.14-7.29) had significantly higher odds of PICU mortality. However, no significant association was found between PICU-acquired hyponatremia and odds of PICU mortality. Even mild sodium fluctuations (4-8mmoL/L) during PICU admission were significantly associated with higher prolonged PICU stay odds. The highest (≥15mmol/L) fluctuations in serum sodium levels during PICU admission were also significantly associated with higher odds of PICU mortality (OR:2.74;95%CI:1.11-6.79). Our findings underscore the importance of closely monitoring serum sodium during PICU admission to improve clinical outcomes.