The prognostic value of systemic immune-inflammation index in patients with aneurysmal subarachnoid hemorrhage: a systematic review.

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating and life-threatening stroke subtype, that has a high disability and fatality rate. By the use of the systemic immune-inflammation index (SII), it is possible to understand the pathophysiology that underlies immune and inflammatory responses and anticipate consequences including delayed cerebral ischemia (DCI), delayed cerebral vasospasm, and functional outcome. A systematic search of the English-language literature in PubMed and Embase was performed to locate articles addressing the usage of SII in aSAH patients. The cutoff value, sensitivity, specificity, and area-under-the curve (AUC) of the receiver operating characteristic (ROC) curve were collected. Four publications were reviewed after applying the exclusion criteria from the 53 included articles. All the studies indicated that higher SII on admission was significantly associated with poor prognosis. The research examined in this paper provides the earliest indications that higher SII predicts DCI, delayed cerebral vasospasm, and functional outcome, even though other medical subspecialties have used this ratio for a long time to make such predictions.