Prevention and Treatment of Hyponatremia in Patients with Subarachnoid Hemorrhage: A Systematic Review.

BACKGROUND: Current guidelines for the management of hyponatremia in patients with subarachnoid hemorrhage (SAH) are not based on a systematic assessment of the literature. We evaluated published studies on the efficacy and safety of current preventative and treatment strategies for hyponatremia in patients with SAH. METHODS: We searched the Cochrane Central Register of Controlled Trials, Embase, MEDLINE, and PubMed for relevant studies. Primary outcomes of interest included neurologic functional outcomes, symptomatic vasospasm, and others. Secondary outcomes included measures of sodium and volume status. RESULTS: We included 5 out of 117 identified studies: 1 before-and-after observational trial (using fludrocortisone) and 4 randomized controlled trials (2 using fludrocortisone; 2 using hydrocortisone). All 5 trials had a high risk of bias in at least 1 domain. We could not perform a meta-analysis of functional outcomes; however, individual studies did not demonstrate statistically significant differences. Mineralocorticoid use did not statistically significantly reduce the incidence of symptomatic vasospasm (relative risk, 0.60; 95% confidence interval, 0.35-1.03; I2 = 0%). The studies did not report other primary outcomes. In the 4 RCTs, mineralocorticoid use reduced natriuresis and volume contraction. CONCLUSIONS: Current evidence does not demonstrate a benefit of preventative treatment with mineralocorticoids in clinically important outcomes, although a difference cannot be ruled out due to imprecision. Larger well-designed trials are needed to establish the impact of mineralocorticoids and fluid and sodium supplementation strategies on clinically relevant outcomes in the prevention and treatment of hyponatremia in patients with SAH.