Quantitation of ischemic events after severe traumatic brain injury in humans: A simple scoring system

BACKGROUND: Cerebral ischemia is recognized as one of the most important mechanisms responsible for secondary brain damage following severe traumatic brain injury (TBI), contributing to an increased mortality and a worse neurologic outcome. METHOD: A simple 5-item scoring system, taking into account the occurrence of specific potentially brain-damaging events (hypoxemia, hypotension, low cerebral blood flow, herniation, and low cerebral perfusion pressure) has been tested in a large population of severe TBI patients. Aims of this retrospective study were to validate the ability of the proposed ischemic score to predict neurologic outcome and to correlate the ischemic score with the results of microdialysis-based neurochemical monitoring and brain tissue oxygen monitoring. FINDINGS: In a population of 172 severe TBI patients, a significant correlation was found between ischemic score and neurologic outcome, both at 3 months (r=-0.32; P<0.01) and at 6 months (r=-0.31; P<0.01). Significant correlations were also found with the most important neurochemical analytes. CONCLUSIONS: The ischemic score proposed here, may be determined during the acute intensive care unit period, and correlates closely with outcome, which can only be determined 3 to 6 months, after injury. It also shows a correlation with neurochemical analytes.