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Risk of Hyponatremia in Patients with Aneurysmal Subarachnoid Hemorrhage Treated with Exogenous Vasopressin Infusion
Marr N, Yu J, Kutsogiannis DJ, Mahmoud SH. Neurocrit Care. 2017; 26: 182-90.
Study Question: Is vasopressin administration associated with the development of hyponatremia in patients with aneurysmal subarachnoid hemorrhage (aSAH)?
Study Description: This was a retrospective, single-center study of patients aged 17 years or older who were admitted to a neurosciences ICU following an aSAH. All patients were treated with endovascular coiling or surgical clipping. Patients were assigned to 1 of 3 groups: “vasopressin” if they received vasopressin, “other pressors” if they received vasoactive agents other than vasopressin, and “no pressors” if they did not receive vasoactive agents. For patients receiving vasoactive agents, serum sodium was recorded before, during, and after drug administration. Hyponatremia was defined as a serum sodium concentration <135 mmol/L.
Results: Twenty patients were treated with vasopressin, 23 were treated with other vasoactive agents, and 63 were not treated with any vasoactive agents. Patients in the vasopressin group had a greater change in mean serum sodium following vasoactive drug initiation compared to patients in the other pressors group (-4.7 ± 6 mmol/L vs. -0.1 ± 2.4 mmol/L; p=0.001). The incidence of hyponatremia was 70% in the vasopressin group, 44% in the other pressors group (p=0.081), and 38% in the no pressors group (p=0.013). In the multivariable logistic regression analysis, vasopressin was associated with increased development of hyponatremia (OR 3.58, 95 % CI 1.02-12.5; p=0.046). No differences in hospital course or disposition were noted between groups.
Conclusion(s): Vasopressin administration may be associated with a reduction in serum sodium concentration in patients with aSAH.
Perspective: Vasopressin may be administered to increase cerebral perfusion or maintain hemodynamic stability in patients with subarachnoid hemorrhage. In the present study, vasopressin administration was associated with a 5 mmol/L decrease in serum sodium concentration. Multivariate logistic regression analysis demonstrated an association between vasopressin administration and the development of hyponatremia. As hyponatremia in patients with subarachnoid hemorrhage has been associated with worse clinical outcomes, including vasospasm and increased hospital length of stay, those patients receiving vasopressin should have their serum sodium closely monitored.