Highs and Lows: Dysnatremia and Patient Outcomes in Aneurysmal Subarachnoid Hemorrhage

Disturbances in serum sodium concentration (dysnatremia) are common following aneurysmal subarachnoid hemorrhage (aSAH), but its direct impact on outcomes is not well understood. This study aimed to examine the association between dysnatremia following aSAH and patient outcomes. A retrospective cohort study of consecutive patients with aSAH who were admitted to an academic referral center between 2015 and 2021 was performed. Multivariate logistic regression was used to test the association of dysnatremia and outcomes including modified Rankin Scale score at 3 months after discharge and vasospasm. Multiple linear regression was used to test the association of hospital length of stay and dysnatremia. We included 320 patients with confirmed aneurysmal etiology (mean [SD] age = 57.8 [14.3] years; 61% female; 70% White). No independent associations were found between hyponatremia or hypernatremia and functional outcome or vasospasm. However, hospital length of stay was longer in patients with hypernatremia (7 more days; 95% confidence interval = 4.4–9.6, P < 0.001) independent of age, Hunt and Hess grade, modified Fisher score, delayed cerebral ischemia, and other hospital complications. Although dysnatremia may not directly impact functional outcome or vasospasm risk, hypernatremia may prolong hospital length of stay. Judicious use of hypertonic saline solutions and avoidance of unnecessary dysnatremia in patients with aSAH should be considered.