Risk of Hyponatremia in Patients with Aneurysmal Subarachnoid Hemorrhage Treated with Exogenous Vasopressin Infusion.

BACKGROUND

Vasopressin is one of the vasopressors used to augment blood pressure in subarachnoid hemorrhage (SAH) patients with clinically significant vasospasm. The purpose of the present study was to determine whether the administration of vasopressin to a population of SAH patients was an independent predictor of developing hyponatremia.

METHODS

A retrospective review on the health records of 106 patients admitted to the University of Alberta Hospital Neurosciences ICU, Edmonton AB, Canada, with SAH from June 2013 to December 2015 was conducted. Serum sodium changes in patients receiving vasoactive drugs were compared. In addition, independent predictors for hyponatremia (Na < 135 mmol/L) were determined using a multivariate logistic regression model.

RESULTS

Patients treated with vasopressin in addition to other vasoactive drugs had significantly higher sodium changes compared to those treated with other vasoactive drugs (-4.7 ± 6 vs -0.1 ± 2.4 mmol/L, respectively, p value 0.001). Hyponatremia occurred in 14 patients (70 %) treated with vasopressin, 10 patients (44 %) treated with vasoactive drugs other than vasopressin (p value 0.081), and 24 patients (38 %) who did not receive any vasoactive drug (p value 0.013). In multivariate logistic regression analysis, when adjusting for disease severity, age, sex, aneurysm location, and treatment, vasopressin was associated with hyponatremia (OR 3.58, 95 % CI, 1.02-12.5, p value 0.046).

CONCLUSIONS

The results of the present study suggest that hyponatremia may be more common in SAH patients treated with exogenous vasopressin compared to those who did not receive it. Serum sodium should be monitored closely when vasopressin is being used in the SAH population. Further studies are needed to confirm the effect of exogenous vasopressin on serum sodium levels in SAH populations.