Neurologic and psychiatric disorders following correction of profound hyponatremia - A cohort study

Rapid correction of profound hyponatremia (serum sodium <125 mmol/L) has been associated with osmotic demyelination syndrome (ODS) but this has been challenged. Potential associations with other neurological and psychiatric diseases have not been studied.

The basis of this study was the Stockholm Sodium Cohort, a laboratory data repository covering inhabitants of the Stockholm Region who had a sodium concentration analyzed (2005-2018, n = 1632,249). Patients admitted with profound hyponatremia for the first time during the study period where sodium correction rates during the first 24 h could be calculated were included. Sodium correction ≤8 and >8 mmol/L/24 h was compared.

Hospitalization with profound hyponatremia occurred in 7623 individuals, 3199 (42.0 %) were males, and the median age was 70 years (IQR 59-80 years). Alcohol misuse was present in 18.3 %, a neurological and/or psychiatric disease in 52.4 % and hypokalemia in 27.9 %. The recommended correction rate ≤8 mmol/L/24 h was adhered to in 3985 (52.3 %) patients. Seven patients (0.09 %) were diagnosed with ODS, six had a correction rate >8 mmol/L/24 h (compared to 1 patient with a correction rate ≤8 mmol/L, P = 0.0441). The risk of new neurological or psychiatric diseases did not differ significantly between those with a correction rate ≤8 mmol/L/24 h and those above in the fully adjusted model (adjusted hazard ratio 1.02 95 %CI 0.89-1.17)) nor in the subgroups.

ODS was rare, however, mainly associated with rapid correction. Consequently, slow correction may be preferable.