Cerebral oxygenation in patients after severe head injury: monitoring and effects of arterial hyperoxia on cerebral blood flow, metabolism and intracranial pressure.

摘要: Early impaired cerebral blood flow (CBF) after severe head injury (SHI) leads to poor brain tissue oxygen delivery and lactate accumulation. The purpose of this investigation was elucidate the relationship between CBF, local dialysate (lact(md)) glucose (gluc(md)), levels (PtiO2) under arterial normoxia. effect increased oxygenation due high fractions inspired (FiO2) on lact(md) CBF explored. A total 47 patients with SHI were enrolled in studies (Glasgow Coma Score [GCS] < 8). first assessed 40 at one time point 96 hours (27 +/- 28 hours) using stable xenon computed tomography (Xe-CT) (30% [FiXe] 35% FiO2). In a second study, sequential double measurements performed 7 FiO2 60% FiO2, respectively, an interval 30 minutes. subsequent 14 underwent normobaric hyperoxia by increasing from 35 5% then 100% over period 6 hours. This done test gluc(md), as measured microdialysis. Changes PtiO2 response changes analyzed calculating reactivity. Oxygen reactivity related 3-month outcome data. gluc(md) compared baseline levels, FiO2. Under normoxic conditions, there significant correlation (R = 0.7; P .001). however, inversely correlated (P .05). undergoing 6-hour challenge, mean 353 (87% baseline), although decreased 38 16% (oxygen reactivity) .01). Monitoring provides valuable information about substrate delivery. Increasing tension (PaO2) effectively PtiO2, reduced same maneuver.