Fast Sodium Correction May Not Independently Raise Demyelination Risk in Severe Hyponatremia

People with severe hyponatremia who develop osmotic demyelination syndrome appear to be corrected too quickly, but a new study suggests that rapid sodium correction itself may not be the independent culprit it has long been assumed to be. In a retrospective case-control analysis published in Neurocritical Care, researchers identified 23 cases of osmotic demyelination syndrome among more than 9,500 adults admitted with profoundly low blood sodium levels, and found that the apparent link with fast correction largely dissolved once other risk factors were taken into account.

The study’s authors note, however, that the evidentiary base behind this guidance rarely accounts for confounding factors that could distort the apparent relationship between correction speed and outcome.

To address that gap, the team led by Dustin G. Mark of the Kaiser Permanente CREST Network examined adults with an initial serum sodium concentration of 120 meq/L or lower who were admitted to a 21-hospital integrated healthcare system between January 1, 2008 and December 31, 2023. Maximum 24-hour sodium correction rates were classified as slow (less than 8 meq/L), moderate (8 to 12 meq/L), or fast (more than 12 meq/L). The researchers used Firth's penalized logistic regression to estimate adjusted odds ratios.

The analysis identified 23 cases of osmotic demyelination syndrome and 9,557 controls without the condition. On the surface, the pattern seemed to confirm conventional teaching: compared with controls, cases were far more likely to have undergone fast sodium correction, at 43 percent versus 24 percent.

That association, however, did not survive statistical adjustment. After accounting for three factors that were themselves strongly linked to the syndrome, the apparent risk from faster correction disappeared. An initial serum sodium of 105 meq/L or lower carried an adjusted odds ratio of 10.3 (95 percent confidence interval 3.3 to 32.3), a history of alcohol abuse carried an adjusted odds ratio of 3.9 (95 percent CI 1.7 to 8.8), and an initial serum potassium below 3.0 meq/L carried an adjusted odds ratio of 3.4 (95 percent CI 1.2 to 9.3).

Once these confounders were included, moderate correction (adjusted odds ratio 0.6, 95 percent CI 0.2 to 2.0) and fast correction (adjusted odds ratio 1.0, 95 percent CI 0.3 to 2.9) showed no statistically significant association with osmotic demyelination syndrome. An odds ratio near 1.0 for fast correction indicates that, in this dataset, rapid correction conferred no measurable excess risk beyond what the underlying risk factors explained.

The authors conclude that faster sodium correction rates seen among osmotic demyelination syndrome cases may be, at least in part, epiphenomena of underlying confounding factors. In other words, the sickest patients, including those with the most profound hyponatremia, severe potassium depletion, or alcohol abuse, may both be more likely to develop the syndrome and more likely to require or receive rapid correction, making correction speed appear causally related when it may be a marker of underlying vulnerability.

As a retrospective, single-healthcare-system case-control study, the analysis establishes association rather than causation, and the small number of cases, 23 in total, limits statistical precision, as reflected in the wide confidence intervals. The findings do not directly test whether slow correction is harmful or unnecessary, and they do not by themselves overturn guideline recommendations. They do, however, suggest that the evidence linking correction speed to osmotic demyelination risk is weaker than commonly assumed, and that patient-level risk factors deserve greater weight in understanding who develops this rare complication.

Subject of Research: The association between sodium correction rates and osmotic demyelination syndrome in severe hyponatremia after accounting for confounding risk factors.

Article Title: Osmotic Demyelination Syndrome in Severe Hyponatremia: Independent Association with Sodium Correction Rates When Accounting for Confounding Risk Factors

Article References: Mark, D. G., Alavi, M., Reed, M. E., & for the Kaiser Permanente CREST Network Investigators (2026). Osmotic Demyelination Syndrome in Severe Hyponatremia: Independent Association with Sodium Correction Rates When Accounting for Confounding Risk Factors. Neurocritical Care. https://doi.org/10.1007/s12028-026-02699-6

Image Credits: AI Generated

DOI: 10.1007/s12028-026-02699-6

Keywords: hyponatremia, osmotic demyelination syndrome, sodium correction, case-control study, retrospective study, confounding factors, neurocritical care, electrolytes, adjusted odds ratio, Kaiser Permanente, Osmotic, Demyelination