Articles: brain-injuries.
-
A new index of cerebral hemodynamics, cerebral hemodynamic reserve (CHR), was evaluated in 12 comatose adults with severe, acute, traumatic, diffuse swelling of the brain, who underwent continuous monitoring with a fiberoptic catheter of the saturation difference in arteriojugular oxyhemoglobin. CHR was assessed as the ratio of changes in global cerebral oxygen extraction to changes in cerebral perfusion pressure (CPP) as a result of spontaneous increases in intracranial pressure (ICP). During the course of hyperventilation (Pco2 in the range of 20 mm Hg) for ICP control below 20 mm Hg, 34 observations were made over the initial 48 hours postinjury. ⋯ This was reflected by the occurrence of baseline normalized cerebral oxygen extraction. It is concluded that in this group of patients, under circumstances of profound hyperventilation, ICP elevations within the normal CPP range may result in decreased cerebral oxygenation, even when the normal CPP would imply otherwise. It is suggested that CHR assessment may provide information regarding the status of intracranial "tightness," insofar as cerebral circulation and oxygenation are concerned.
-
Journal of neurosurgery · Nov 1991
Case ReportsCerebral circulation and metabolism after severe traumatic brain injury: the elusive role of ischemia.
Although experimental and pathological studies suggest an important role for ischemia in the majority of fatal cases of traumatic brain injury, ischemia has been a rare finding in most clinical studies of cerebral blood flow (CBF) in head-injured patients. The hypothesis of the present study was that cerebral ischemia occurs in the first few hours after injury, but that CBF measurements have not been performed early enough. Early measurements of CBF (by the 133Xe intravenous method) and arteriovenous oxygen difference (AVDO2) were obtained in 186 adult head-injured patients with a Glasgow Coma Scale score of 8 or less, and were correlated with neurological status and outcome. ⋯ In some cases, ischemia was successfully treated by reducing hyperventilation or inducing arterial hypertension. These results support the above hypothesis, and suggest that early ischemia after traumatic brain injury may be an important factor determining neurological outcome. Moreover, these data indicate that early hyperventilation or lowering of blood pressure to prevent brain edema may be harmful.
-
Brain injury : [BI] · Oct 1991
ReviewCritical analysis of the concept of sensory stimulation for patients in vegetative states.
The practice of coma arousal and sensory stimulation is becoming the focus of heated debate. There is no theory on which patients may benefit, at what time in their recovery, or how the 'arousal' or 'stimulation' procedures should be applied. This paper considers some of the information processing mechanisms that are important mediators of arousal and awareness, pointing to some of the weaknesses in current practices and suggesting alternative approaches. Recommendations for a conceptual model of sensory stimulation are given that might provide a more scientific perspective to those who use such methods.
-
Critical care medicine · Oct 1991
Comparative StudyEffect of associated injuries and blood volume replacement on death, rehabilitation needs, and disability in blunt traumatic brain injury.
To examine the effects of associated injuries on death, disability, rehabilitation needs, and cost in patients with blunt traumatic brain injury. ⋯ In blunt traumatic brain injury, the addition of major visceral or extremity injuries, with need for blood replacement or shock, increases the risk of death, the need for rehabilitation, and the costs of disability.