Glucocorticoid treatment is associated with ICU-acquired hypernatremia: a nested case-control study

Background Hypernatremia is a major electrolyte disorder associated with death among critically ill patients. Glucocorticoid therapy may cause hypernatremia in refractory septic shock patients, but the association between glucocorticoid and intensive care unit (ICU)-acquired hypernatremia (IAH) remains unclear. The aim of this study was to clarify whether glucocorticoid administration was associated with IAH. Methods This was a nested case-control study using data from an established cohort including 121 IAH cases identified from 1756 patients who were admitted to ICU in a tertiary care facility in Japan. We included patients who were admitted with a normal range of serum sodium concentrations (130-149 mEq/L) from January 1, 2013 to December 31, 2015 and remained in ICU for >= 2 days. Hypernatremia was defined as serum sodium concentration >= 150 mEq/L. Each case was matched to one control. Results Multivariable conditional logistic regression revealed high-dose glucocorticoid {odds ratio (OR), 4.15 [95% confidence interval (CI) 1.29-13.4]}, acute kidney injury (AKI) [OR, 2.72 (95% CI 1.31-5.62)], and osmotic diuretics [OR, 3.44 (95% CI 1.41-8.39)] to be significantly associated with IAH. The contents and amounts of fluid infusion were not significantly associated with IAH. There were also significant duration-response effects between duration of glucocorticoid use and IAH; however, pulse glucocorticoid administration was not associated with IAH. Conclusion In this nested case-control study, we demonstrated a significant association between IAH and high-dose glucocorticoid with significant duration-response effects. Serum sodium concentrations should be monitored carefully in critically ill patients administered prolonged high-dose glucocorticoid.