Saline versus Balanced Crystalloids for Adults with Aneurysmal Subarachnoid Hemorrhage: A Subgroup Analysis of the SMART Trial.

Background: Whether the composition of intravenous crystalloid solutions affects outcomes in adults with aneurysmal subarachnoid hemorrhage (aSAH) remains unknown. Therefore, we determined whether the use of saline is associated with lower risk of disability and death in aSAH patients compared to balanced crystalloids. Methods: We conducted a post hoc subgroup analysis of the Isotonic Solutions and Major Adverse Renal Events Trial (SMART), a pragmatic, unblinded, cluster-randomized, multiple-crossover clinical trial that enrolled 15,802 adults between June 2015 and April 2017. We compared intravenous administration of saline to balanced crystalloids in consecutively enrolled aSAH patients aged 18 years or older whose ruptured aneurysm was procedurally secured at a single academic center in the United States. The primary outcome was the score on the modified Rankin scale (mRS, range, 0 [no symptoms] to 6 [death]) at 90 days obtained from a prospective institutional stroke registry. Secondary outcome included death by 90 days. Logistic or proportional odds regression models were used to test for between-group differences adjusted for age, hypertension, aSAH grade, and procedure type. Results: Of the 79 aSAH patients procedurally treated during the SMART study period, 78 were enrolled (median age, 58 years; IQR, 49 to 64.5; 64% female), with 41 (53%) assigned to saline and 37 (47%) to balanced crystalloids. Plasma-Lyte was the primary balanced crystalloid used. Among 72 patients with 90-day mRS assessment, the adjusted common odds ratio, aOR, for mRS was 0.68 (95% CI, 0.28-1.63; P=0.39), with values less than 1.0 favoring saline. By 90 days, 2/39 patients (5%) in the saline group and 9/35 (26%) in the balanced-crystalloids group had died (aOR, 0.06; 95% CI, 0.00-0.50; P=0.02). Conclusions: Among procedurally treated aSAH patients, the risk of disability or death at 90 days did not significantly differ between saline and balanced crystalloids. Death occurred less frequently with saline than balanced crystalloids.