The Role of Hypotension and Hypoxia in Determining Outcome Following Aneurysmal Subarachnoid Hemorrhage

ABSTRACT

OBJECTIVE: It is well known that hypotension and hypoxia are detrimental secondary brain insults and have deleterious effects on the outcome of patients with severe closed head injuries. We evaluated the effect of hypotension and hypoxia on aneurysmal subarachnoid hemorrhage(SAH). METHODS: We reviewed retrospectively 159 consecutive operated aneurysmal SAH cases. Hypotension and hypoxia were identified during the patients' operation and intensive care unit hospitalization. We analyzed them as four mutually exclusive categories neither hypotension nor hypoxia(normal), hypotension only, hypoxia only, hypotension and hypoxia combined. The outcome following aneurysmal SAH was determined by the Glasgow outcome scale score and then analyzed. The incidence of occurrence of hydrocephalus and clinical vasospasm were also analyzed. RESULTS: 22 patients(13.8%) experienced hypotension and 16 patients(10.1%) experienced hypoxia and 8 patients(5.0%) experienced both hypotension and hypoxia. The incidence of hydrocephalus in combined category(75.0%) was significantly higher than normal category(14.3%). The incidence of clinical vasospasm in hypotension category(77.3%) and combined category(87.5%) were significantly higher than normal category(38.1%, p<0.05). The outcome of hypotension category and combined category were significantly unfavorable compared with normal category(p<0.05). Furthermore, the impact of hypotensive insult was much greater on good grade Hunt-Hess patients. CONCLUSION: The detrimental secondary brain insults as hypotension and hypoxia occurred not infrequently in aneurysmal SAH patients and had deleterious effects on the outcome of aneurysmal SAH patients. These data suggest that hypotension during critical period in aneurysmal SAH patients should be avoided to improve outcome.