Risk factors responsible for the volume of hemorrhage in aneurysmal subarachnoid hemorrhage.

Background: Aneurysmal subarachnoid hemorrhage (aSAH) is a medical emergency with a high mortality and morbidity. There is a marked association of the ensuing neurological functional deficits following aSAH with the volume of hemorrhage. The volume of intracranial hemorrhage in aSAH is usually quantified by the revised Fisher grades. Materials and Methods: A total of 155 patients who suffered from aSAH were evaluated for risk factors that led to an increased volume of intracranial hemorrhage. These included various demographic factors, the medical history, the preadmission blood pressure, and the aneurysm characteristics. Results: The number of aneurysms was significantly related to poor revised Fisher grades (grade 3 or 4; P = 0.016). Thus, the presence of multiple aneurysms (2-4) was a significant risk factor responsible for a poor modified Fisher grade (odds ratio [OR] = 4.0, P = 0.004). Significantly higher risk of intracranial hemorrhage was also observed for aneurysms located on the the internal carotid artery (ICA), anterior communicating artery (ACOA), or middle cerebral artery (MCA) when compared with other sites (P < 0.001). Bleeding in ACOA was significantly associated with a poor Fisher's grade (OR = 4.3, P = 0.025). Additionally, the preadmission diastolic blood pressure (DBP) alone was significantly associated with a poor Fisher grade (P = 0.024). Conclusion: Preadmission DBP, multiple aneurysms, and aneurysms of the ACOA are associated with markedly increased volume of hemorrhage as evaluated by the revised Fisher grades. Thus, patients harboring an intracranial aneurysm having the above mentioned features should seek an early intervention in order to prevent the occurrence of aSAH.