Sodium Correction Rates and Associated Outcomes Among Patients With Severe Hyponatremia : A Retrospective Cohort Study.

Abstract

Slow correction of severe hyponatremia is recommended to prevent osmotic demyelination syndrome but is associated with higher mortality. To examine the association between sodium correction rates and death or delayed neurologic events. Retrospective cohort study. Twenty-one community hospitals of an integrated health system in northern California. Adults hospitalized with a serum sodium level of 120 mEq/L or lower between 2008 and 2023. Maximum 24-hour rate of serum sodium correction (slow [<8 mEq/L], medium [8 to 12 mEq/L], or fast [>12 mEq/L; reference]). The primary outcome was a composite of 90-day death or delayed neurologic events (new demyelination, paralysis, epilepsy, or altered consciousness between 3 and 90 days from admission). Standardized risk differences (RDs) were generated using targeted maximum likelihood estimation. Heterogeneity of effect was assessed across grades of predicted risk. 13 988 patients were hospitalized with severe hyponatremia during the study period (median age, 74 years; 63% female). Comorbidities included congestive heart failure (24%), liver disease (18%), alcohol dependence (14%), and metastatic cancer (10%). The primary outcome occurred in 3000 patients (21%); 90-day death occurred in 2554 (18%), and 90-day delayed neurologic events occurred in 587 (4%). Compared with slow 24-hour sodium correction, both medium (RD, -5.6 percentage points [95% CI, -7.1 to -4.0 percentage points]) and fast (RD, -9.0 percentage points [CI, -11.1 to -6.9 percentage points]) correction rates were associated with lower adjusted risk for the primary outcome. Risk differences increased with higher predicted risk, whereas risk ratios remained similar. Residual confounding; outcome ascertainment using diagnostic codes. Faster sodium correction is associated with lower risk for 90-day death or delayed neurologic events. Treatment guidelines should be reexamined. The Permanente Medical Group Rapid Analytics Unit Program.