Risk Factors and Total Sodium Dose Associated With Hyponatremia Overcorrection: A Retrospective Cohort Study.

BACKGROUND: Hyponatremia overcorrection may cause serious irreversible neurologic impairment. Although studies have identified the risk factors and optimal treatment regimens for hyponatremia, findings have been inconsistent; furthermore, current treatment guidelines provide recommendations that do not consider patient-related factors. OBJECTIVES: This study aimed to identify the risk factors of hyponatremia overcorrection and assess the relationship between administered sodium dose and subsequent changes in serum sodium levels. METHODS: This retrospective cohort study included 212 patients with hyponatremia admitted to the emergency department of a tertiary medical center. The primary study outcome was hyponatremia overcorrection defined as >12 mEq/L increase in serum sodium 12 h after the baseline. The secondary study outcome was hyponatremia overcorrection defined as >8 mEq/L increase in serum sodium at 12 h after the baseline. RESULTS: Overcorrection of >8 and 12 mEq/L at 12 h occurred in 39 (18.4%) and 16 (7.5%) patients, respectively. Multivariable logistic regression analysis revealed that low urine osmolality (<150 mOsm/kg) and total sodium dose of >4.6 mEq/kg over 12 h were significant risk factors of hyponatremia overcorrection. Serum sodium changes were significantly higher in the group with >4.6 mEq/kg/12 h than in the group with >3.4 mEq/kg/12 h (9.4 ± 5.3 mEq/L vs. 5.1 ± 4.0 mEq/L, p = 0.001). CONCLUSION: Low urine osmolality and total sodium dose of >4.6 mEq/kg/12 h were significant risk factors of overcorrection in patients with hyponatremia. Calculating the total sodium dose might help prevent hyponatremia overcorrection.