Cerebral oxygenation in major pediatric trauma: its relevance to trauma severity and outcome

IntroductionTrauma is the commonest cause of death in the pediatric population, which is prone to diffuse primary brain injury aggravated by secondary insults (eg, hypoxia, hypotension). Standard monitoring involves intracranial pressure (ICP) and cerebral perfusion pressure, which do not reflect true cerebral oxygenation (oxygen delivery [Do2]). We explore the merits of a brain tissue oxygen–directed critical care guide.MethodsSixteen patients with major trauma (Injury Severity Score, >16/Pediatric Trauma Score [PTS], <7) had partial pressure of brain tissue oxygen (Pbto2) monitor (Licox; Integra Neurosciences, Plainsboro, NJ) placed under local anesthesia using twist-drill craniostomy and definitive management of associated injuries. Pbto2 levels directed therapy intensity level (ventilator management, inotrops, blood transfusion, and others). Patient demographics, short-term physiological parameters, Pbto2, ICP, Glasgow Coma Score, trauma scores, and outcomes were analyzed to identify the patients at risk for low Do2.ResultsThere were 10 males and 6 females (mean age, 14 years) sustaining motor vehicle accident (14), falls (1), and assault (1), with a mean Injury Severity Score of 36 (16-59); PTS, 3 (0-7); and Revised Trauma Score, 5.5 (4-11). Eleven patients (70%) had low Do2 (Pbto2, <20 mm Hg) on admission despite undergoing standard resuscitation affected by fraction of inspired oxygen, Pao2, and cerebral perfusion pressure (P = .001). Eubaric hyperoxia improved cerebral oxygenation in the low-Do2 group (P = .044). The Revised Trauma Score (r = 0.65) showed moderate correlation with Pbto2 and was a significant predictor for low Do2 (P = .001). In patients with Pbto2 of less than 20 mm Hg, PTS correlated with cerebral oxygenation (r = 0.671, P = .033). The mean 2-hour Pbto2 and the final Pbto2 in survivors were significantly higher than deaths (21.6 vs 7.2 mm Hg [P = .009] and 25 vs 11 mm Hg [P = .01]). Although 4 of 6 deaths were from uncontrolled high ICP, PTS and 2-hour low Do2 were significant for roots for mortality.ConclusionsPbto2 monitoring allows for early recognition of low-Do2 situations, enabling appropriate therapeutic intervention.