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The most common causes of hypoxia are partial airway obstruction, hypoventilation, aspiration pneumonia, and atelectasis. Patients with decreased consciousness or signs of brain stem dysfunction have the greatest risk of airway compromise because of impaired oropharyngeal mobility and loss of protective reflexes.182–184 The prognosis of patients who require endotracheal intubation generally is poor; ≈50% of these patients are dead within 30 days after stroke.185,186 Pneumonia is among the leading complications of stroke and is an important cause of death after the cerebrovascular event.187 It is most likely to develop among patients who are seriously ill, and prevention of early aspiration and protection of the airway may be a way to lessen this complication. Elective intubation also may help in the management of patients who have severely increased levels of intracranial pressure or have malignant brain edema after stroke.185,188 No clinical trial has tested the utility of endotracheal intubation in the management of critically ill patients with stroke, and we anticipate that none will be done. It is generally agreed that an endotracheal tube should be placed if the airway threatened.182,188 After ischemic stroke, some patients develop Cheyne-Stokes pattern of respiration, with decreases in oxygen saturation that can be readily reversed with oxygen supplementation.189 A small pilot study found that high-flow oxygen may be associated with a transient improvement in neurological impairments.190 The results of a controlled study do not support the use of supplemental oxygen at 3 L/min for most patients with acute ischemic stroke.191 However, patients with acute stroke should be monitored with pulse oximetry with a target oxygen saturation level ≥92%.25,192 Most patients with acute stroke do not need supplemental oxygen; however, if pulse oximetry or blood gas determination indicates hypoxia, oxygen should be administered. Hyperbaric oxygen may be used to treat patients with ischemic neurological symptoms secondary to air embolism or caisson disease.193 Studies that have tested the use of hyperbaric oxygen in stroke have been inconclusive or have shown that the intervention does not improve outcomes.194–196 Data from a small trial suggest that hyperbaric oxygen therapy may be harmful.196 A systematic review found no evidence that hyperbaric oxygen improved outcomes after stroke or brain injury.197 At present, data do not support the routine use of hyperbaric oxygen in the treatment of patients with acute ischemic stroke. B. Temperature Increased body temperature (fever) in the setting of acute ischemic stroke is associated with poor neurological outcome (increased risk of morbidity and mortality), possibly secondary to increased metabolic demands, enhanced release of neurotransmitters, and increased free radical production.198–205 The source of any fever should be ascertained. The fever may be secondary to a cause of stroke, such as infective endocarditis, or may represent a complication, such as pneumonia. Because of the negative effects of fever, lowering an acutely elevated body temperature might improve the prognosis of patients with stroke.206 Measures include antipyretic medications and cooling devices. Small clinical trials have tested the utility of aspirin, ibuprofen, or acetaminophen in lowering body temperatures and in improving outcomes after stroke. Sulter et al207 found that either aspirin or acetaminophen was modestly successful in achieving normothermia but that patients with a temperature >38°C were relatively unresponsive to treatment. In a small, randomized trial, Kasner et al208 administered 3900 mg of acetaminophen daily to afebrile patients with stroke. They concluded that the medication might prevent hyperthermia or modestly promote hypothermia but that the effects were not likely to have a robust clinical impact. Dippel et al209 tested 2 different doses of acetaminophen in a small clinical trial. They concluded that a daily dosage of 6000 mg might have a potential beneficial effect in lowering body temperature. A small placebo-controlled trial found that
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