Definition and Prevalence
Subarachnoid hemorrhage (SAH) refers to bleeding into the space between the arachnoid membrane and the pia mater of the brain. Traumatic brain injury accounts for about 95% of all SAH, the vast majority of the remaining 5% are the result of a ruptured aneurysmal SAH (de Rooij, 2007).
Initial presentation, treatment, and management of patients with SAH will vary based on the cause of SAH (trauma vs spontaneous). This course will explore the etiology, pathophysiology, treatment and management of the most common cause of spontaneous SAH; ruptured aneurysm.
Aneurysmal SAH is a significant cause of morbidity and mortality. "About 35% of patients die after the first aneurysmal subarachnoid hemorrhage; another 15% die within a few weeks because of a subsequent rupture. After 6 mo, a 2nd rupture occurs at a rate of about 3%/yr (Giraldo 2013)".
The 2003 Nationwide Inpatient Sample (NIS) indicates that the United States had an annual aSAH hospital discharge rate of 14.5 per 100,000 adults (Shea A.M., 2007). The total U.S. incidence of aSAH is likely to be higher because the NIS records do not include deaths that occur prior to admission to hospital. Aneurysmal SAH is more prevalent in people over 50 and in women, African Americans, and Hispanics (Connolly et al., 2012).
Spontaneous rupture of a cerebral aneurysm is responsible for 95% of all SAH.