Neurocritical care
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To evaluate the effects of the neurological "wake-up test" (NWT), defined as interruption of continuous propofol sedation and evaluation of the patient's level of consciousness, on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in patients with severe subarachnoid hemorrhage (SAH) or traumatic brain injury (TBI). ⋯ When continuous propofol sedation was interrupted and NWT was performed in severely brain-injured patients, the mean ICP and CPP levels were modestly increased. A subset of patients showed more pronounced changes. To date, the role of the NWT in the neurointensive care of TBI and SAH patients is unclear. Although the NWT is safe in the majority of patients and may provide useful clinical information about the patient's level of consciousness, alternate monitoring methods are suggested in patients showing marked ICP and/or CPP changes during NWT.
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Anemia predicts poor outcome following aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that this association would be stronger among patients with more severe SAH, since these patients are likely to be more vulnerable to secondary brain injury in the form of reduced cerebral oxygen delivery. ⋯ Lower Hb levels are associated with worse outcomes regardless of SAH severity or the development of vasospasm. This finding may imply that a lower Hb concentration is largely a marker for a greater degree of systemic illness, rather than necessarily causing direct harm. However, the association is somewhat stronger among patients with more severe SAH. Thus, if there is a benefit for maintaining higher Hb levels with transfusions or erythropoietin, it may be more pronounced among these patients.
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Comparative Study
Placement of external ventricular drains and intracranial pressure monitors by neurointensivists.
External ventricular drains (EVDs) and intracranial pressure (ICP) monitors are widely used in the Neurological Critical Care Unit (NCCU) to measure ICP and divert cerebrospinal fluid (CSF). EVDs and ICP monitors have historically been placed by neurosurgeons; however, with recent staffing of NCCUs by neurointensivists, a growing number of EVDs and ICP monitors are being placed by these specialists. ⋯ Patients receiving ICP monitors had no complications. These complication rates are comparable to published rates, which suggest that placement of EVDs and ICP monitors by neurointensivists may be safe and effective. However, small sample size (n = 36) prohibits definitive safety and efficacy conclusions. For this reason, further research analyzing a larger patient sample is warranted.
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Vasospasm is a major complication of aneurysmal subarachnoid hemorrhage (SAH) and affects clinical outcome. The ability to predict cerebral vasospasm after SAH would allow the neuro-intensivist to institute preemptive and more aggressive therapy. ⋯ Hijdra sum score and a history of smoking are the strongest predictors of cerebral vasospasm on angiography. HSS is superior to the MFS as a radiologic grading tool to predict occurrence of angiographic vasospasm after aneurysmal subarachnoid hemorrhage.
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Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a serious complication resulting in delayed neurological deficit, increased morbidity, mortality, longer hospital stays, and rehabilitation time. It afflicts approximately 35 per 100,000 Americans per year, and there is currently no effective therapy. We present in vitro data suggesting that increasing intrinsic nitric oxide relaxation pathways in vascular smooth muscle via dopaminergic agonism ameliorates cerebral vasospasm after SAH. ⋯ Cerebral vasospasm is significantly reversed in a functional measure of vasospasm in vitro by dopamine, via a D(2)R-mediated pathway. The increase in NOS protein seen in both the endothelium and vascular smooth muscle in response to CSF(V) is enhanced by dopamine, also in a D(2)R-dependent mechanism.