Stroke; a journal of cerebral circulation
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Clinical Trial
Neither arm nor face warming reduces the shivering threshold in unanesthetized humans.
Hand warming and face warming, combined with inhalation of heated air, are reported to suppress shivering. However, hand or face temperature contributes only a few percent to control of shivering. Thus, it seems unlikely that manipulating hand or facial skin temperature alone would be sufficient to permit induction of therapeutic hypothermia. We tested the hypothesis that focal arm (forearm and hand) warming or lower facial warming, combined with inhalation of heated and humidified gas, only minimally reduces the shivering threshold (triggering core temperature). ⋯ Focal arm or face warming did not substantially reduce the shivering threshold in unanesthetized volunteers. It thus seems unlikely that these nonpharmacological modalities will substantially facilitate induction of therapeutic hypothermia.
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The pressure-flow velocity relationship in the cerebral circulation is characterized by the critical closing pressure (CCP), which is the pressure at which flow ceases, and the linear slope of a plot between pressure and flow velocity. It has been suggested, but not validated, that CCP can be determined from arterial blood pressure (ABP) and transcranial Doppler (TCD) recordings during the cardiac cycle. We studied a group of patients in whom ventricular fibrillation (VF) was induced. The time interval before defibrillation enabled calculation of CCP from data in which flow approached zero. These estimates were compared with values calculated before and after fibrillation and during regular heartbeats. ⋯ CCP can be accurately estimated from regular heartbeat data and is an important factor in regulation of the cerebral circulation.
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A simple clinical scale of intracerebral hemorrhage (ICH), comprising the Glasgow Coma Scale score, age, infratentorial origin, ICH volume, and intraventricular hemorrhage, was recently shown to predict 30-day mortality. We studied how well the original ICH Score would predict morbidity and mortality and determined whether modification would improve the predictions. ⋯ All 3 ICH Scores are simple clinical grading scales. As reliable predictors of good outcome and/or mortality, they are useful in clinical research studies and standardization of clinical protocols.
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Phenylpropanolamine (PPA) and pseudoephedrine are sympathomimetics contained in over-the-counter cold preparations. A case-control study linked PPA use with hemorrhagic stroke in women. Twenty-two patients with stroke associated with use of these drugs are described. ⋯ Stroke related to over-the-counter sympathomimetics was associated with acute hypertension and/or vasospasm or angiitis mechanisms, most related to the use of PPA; however, stroke also occurred with the use of other sympathomimetics, particularly pseudoephedrine. Although stroke complications occurred when doses were used that were higher than recommended doses, apparently there is also a stroke risk when these agents are taken properly.