CONTINUOUS REGIONAL CEREBRAL CORTICAL BLOOD-FLOW MONITORING IN HEAD-INJURED PATIENTS

CONTINUOUS REGIONAL CEREBRAL cortical blood flow (rCoBF) was monitored with thermal diffusion flowmetry in 56 severely head-injured patients . Adequate, reliable data were accumulated from 37 patients (21 acute subdural hematomas, 10 cerebral contusions, 4 epidural hematomas, and 2 intracerebral hematomas). The thermal sensor was placed at the time of either craniotomy or burr hole placement. In 15 patients, monitorin g was initiated within 8 hours of injury. One-third of the comatose pa tients monitored within 8 hours had rCoBF measurements of 18 ml per 10 0 g per minute or less, consistent with previous reports of significan t ischemia in the early postinjury period. Initial rCoBF measurements were similar in the patients with Glasgow Coma Scale scores of 3 to 7 and in those with scores of 8 or greater. In patients with poor outcom es, rCoBF measurements did not change significantly from initial measu rements; however, in those patients who had better outcomes, final rCo BF measurements were higher than initial rCoBF measurements. The patie nts who had better outcomes experienced normalization of rCoBF during the period of monitoring, and patients with poor outcomes had markedly reduced final rCoBF. These changes were statistically significant. Wh en management was based strictly upon the intracranial pressure, examp les of inappropriate treatment were found. For example, hyperemia and increased intracranial pressure treated with mannitol caused further r CoBF increase, and elevated intracranial pressure with low cerebral bl ood flow treated with hyperventilation increased the severity of ische mia. In 3 (5%) of 56 patients, wound infections developed. Continuous rCoBF monitoring in head-injured patients offers new therapeutic and p rognostic insights into their management.