Clinical question: Does the correction rate for hospitalized adults with severe hyponatremia correlate with mortality or length of stay?
Background: Hyponatremia is a commonly encountered problem among medically hospitalized patients, with increased prevalence among patients with comorbidities or older age. European and U.S. clinical practice guidelines recommend limits to correction rates in the first 24 to 48 hours to avoid the development of osmotic demyelination syndrome (ODS). However, more recent publications have suggested that rapid (defined here as at least eight to 10 mEq/L per 24 hours) correction rates are associated with lower mortality and no increase in occurrence of ODS compared to slower rates (slow defined here as less than eight, or as six to 10, mEq/L; and very slow as less than four to six mEq/L per 24 hours).
Study design: Systematic review and meta-analysis that included 16 cohort studies (14 retrospective, two prospective)
Setting: 11 countries, 249 sites
Synopsis: 11,811 patients with severe hyponatremia (sodium below 120 mEq/L) were included. Rapid correction was associated with 32 (OR, 0.67; 95% CI, 0.55 to 0.82) and 221 (OR, 0.29; 95% CI, 0.11 to 0.79) fewer in-hospital deaths per 1,000 treated patients compared with slow and very slow correction, respectively (moderate-certainty evidence). Rapid correction was also associated with 61 (RR, 0.55; 95% CI, 0.45 to 0.67) and 134 (RR, 0.35; 95% CI, 0.28 to 0.44) fewer deaths per 1,000 treated patients at 30 days, as well as a reduction in length of stay of 1.20 (95% CI, 0.51 to 1.89) and 3.09 (95%CI, 1.21 to 4.94) days, compared with slow and very slow correction, respectively (low-certainty evidence). There was no statistically significant increase in ODS events.
There are important limitations to this study, including the heterogeneity of the studies and the non-insignificant presence of confounders. Notably, primary and secondary outcomes were not available in all the studies. Additionally, the authors were not able to assess for chronicity of hyponatremia or patients’ symptoms and could not perform sub-group analysis to account for the impact of co-morbidities or co-occurring acute medical conditions.
Bottom line: Very slow correction in patients with hyponatremia in the range of 115 to 120 mEq/L may be associated with a higher mortality and length of stay without an increased rate of ODS when compared to more rapid correction, but potential confounders make causality uncertain.
Citation: Ayus JC, et al. Correction rates and clinical outcomes in hospitalized adults with severe hyponatremia: a systematic review and meta-analysis. JAMA Intern Med. 2025;185(1):38-51. doi:10.1001/jamainternmed.2024.5981.
Dr. Clark is a hospital medicine attending physician at Maine Medical Center in Portland, Maine.