Neurocritical care
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Delayed cerebral ischemia after subarachnoid hemorrhage (SAH) may be affected by a number of factors, including cerebral blood flow and oxygen delivery. Anemia affects about half of patients with SAH and is associated with worse outcome. Anemia also may contribute to the development of or exacerbate delayed cerebral ischemia. ⋯ The effects may vary with disease severity or the presence of vasospasm, but it remains unclear whether RBCTs are a marker of disease severity or a cause of worse outcome. Erythropoietin data are limited. The literature review further suggests that the results of the Transfusion Requirements in Critical Care Trial and subsequent observational studies on RBCT in general critical care do not apply to SAH patients and that randomized trials to address the role of RBCT in SAH are required.
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Magnesium offers theoretic vascular and neuroprotective benefits for patients with subarachnoid hemorrhage. An electronic literature search was conducted to identify original research studies describing intravenous magnesium treatment in patients with SAH published in English between January 1990 and October 2010. ⋯ Due to inconsistently reported benefits and the occurrence of side effects, phase II data suggested that intravenous magnesium for SAH provided either no overall net benefit or uncertain trade-offs. Benefit was likewise not supported in the single phase III clinical trial.
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Delayed cerebral ischemia occurs in about 30% of patients during the first 2 weeks after subarachnoid hemorrhage, and can result in substantial disability and death. Research studies investigating the incidence of delayed cerebral ischemia and strategies for prevention and treatment are hampered by inconsistent use of terminology and definitions for this complication, and by reliance on indirect surrogate markers of ischemia. ⋯ Original research studies and consensus panel recommendations for definitions support limiting the use of combined measures that include both clinical and radiographic assessments, as well as indirect measures, and the current usage of the term vasospasm. Cerebral infarction was supported as the most appropriate definition for delayed cerebral ischemia in the context of clinical trials.
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Review
Summary of evidence on immediate statins therapy following aneurysmal subarachnoid hemorrhage.
Statins were shown to have neuroprotective effects, with reduced vasospasm and delayed ischemic deficits in statin-treated patients after aneurysmal subarachnoid hemorrhage in two small, randomized, controlled clinical trials published in 2005. This review consolidated data from available published studies evaluating statin treatment for subarachnoid hemorrhage. A literature search was conducted to identify original research studies published through October 2010 testing immediate treatment with a statin in statin-naïve patients following aneurysmal SAH. ⋯ Despite inconsistent results among studies, a meta-analysis of randomized controlled data showed a significant reduction in delayed ischemic deficits with statins. Effect on vasospasm was more difficult to determine, due to differences in definitions used among studies. Interpretations from observational studies were limited by the use of relatively small sample sizes, historical controls, and treatment variability.
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Disruption of the hypothalamic-pituitary-adrenal axis may occur after aneurysmal subarachnoid hemorrhage, resulting in hypopituitarism. An electronic literature search was conducted to identify articles with English-language abstracts published between 1980 and March 2011 that addressed hypothalamic-pituitary-adrenal axis insufficiency and hormone replacement. A total of 18 observational and prospective, randomized studies were selected for this review. ⋯ Overall, acutely after subarachnoid hemorrhage, cortisol levels may initially be supranormal, decreasing toward normal levels over time. During the months to years after subarachnoid hemorrhage, pituitary deficiency may occur in up to one in three patients. Limited data suggest modest outcome benefits with fludrocortisone and no benefit or harm from corticosteroids.