Spontaneous subarachnoid hemorrhage: A primer for acute care practitioners.

Subarachnoid hemorrhage (SAH) refers to intracranial bleeding into the cerebrospinal filled space beneath the arachnoid membrane that covers the brain. It is further defined as a spontaneous SAH when not associated with trauma. The commonest single cause is rupture of a saccular (i.e. a small bag-shaped or pouch-shaped) intracranial aneurysm, arising from the larger conducting arteries traveling through the subarachnoid space at the base of the brain. As these are high-pressure and higher-volume arterial hemorrhages, aneurysmal subarachnoid hemorrhages (aSAH) are associated with high early mortality and substantial long-term morbidity. But, as we outline below, prompt and collaborative multidisciplinary care can improve the likelihood and quality of survival. Accordingly, we offer the following primer as a common resource to increase knowledge and collaborative care.