J Trauma
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Severe head injury often causes an increase in intracranial pressure (ICP) and decreases in cerebral blood flow (CBF) and cerebral oxygen delivery (CO2del). To determine if this reduction in CBF and CO2del would produce cerebral ischemia and if this reduction would be abrogated by maintaining global cerebral perfusion pressure (CPP), we studied CPP, ICP, CBF, CO2del, cerebral oxygen extraction ratio (CO2ER), and cortical water content (CWC) in a porcine model of focal cryogenic brain injury. Fifteen mature swine were randomized to two groups. ⋯ Cryogenic injury significantly increased the CWC in the lesioned hemisphere. These data indicate that focal brain injury results in persistent ischemia despite the normalization of CPP, suggesting that a significant increase in cerebral vascular resistance (CVR) occurs after brain injury. We conclude that in addition to maintenance of CPP, intervention to reduce CVR may be important in the management of brain injury.
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We reviewed the records of 1538 mild head injury patients admitted during a 4 1/2-year period to the Southern New Jersey Regional Trauma Center. All patients had experienced brief loss of consciousness or amnesia, but had a normal or near normal neurologic examination on admission, with Glasgow Coma Scale (GCS) scores of 13-15 and no focal neurologic deficit. Routine urgent cranial CT scans were obtained on all patients, and correlations between skull fractures and intracranial lesions investigated. ⋯ We conclude that clinical observation with or without skull x-ray films is inadequate to rule out potentially dangerous intracranial lesions in apparently mild head injuries. If there is a history of loss of consciousness or amnesia, an immediate CT scan is indicated. If the results of the CT scan are normal and there are no other indications for admission, these patients may be safely discharged.