State of Cerebrovascular Autoregulation Correlates with Outcome in Severe Infant/Pediatric Traumatic Brain Injury

Abstract

Objective: It could be shown in adults with severe traumatic brain injury (TBI) that the functional status of cerebrovascular autoregulation (AR), determined by the pressure reactivity index (PRx), correlates with and even predicts outcome. We investigated PRx and its correlation with outcome in infant and pediatric TBI. Methods Ten patients (median age 2.8 years, range 1 day to 14 years) with severe TBI (Glasgow Coma Scale score <9 at presentation) underwent long-term computerized intracranial pressure (ICP) and mean arterial pressure (MAP) monitoring using dedicated software for continuous determination of cerebral perfusion pressure (CPP) and PRx. Outcome was determined at discharge and at follow-up at 6 months using the Glasgow Outcome Scale (GOS) score.

Results: Median monitoring time was 182 h (range 22-355 h). Seven patients underwent decompressive craniectomy to control ICP during treatment in the intensive care unit. Favorable outcome (GOS 4 and 5) was reached in 4 patients, an unfavorable outcome (GOS 1-3) in 6 patients. When dichotomized to outcome, no correlation was found with ICP and CPP, but median PRx correlated well with outcome (r = -0.79, p = 0.006) and tended to be lower for GOS 4 and 5 (-0.04) than for GOS 1-3 (0.32; p = 0.067).

Conclusion: The integrity of AR seems to play the same fundamental role after TBI in the pediatric population as in adults and should be determined routinely. It carries an important prognostic value. PRx seems to be an ideal candidate parameter to guide treatment in the sense of optimizing CPP, aiming at improvement of cerebrovascular autoregulation (CPPopt concept).

Keywords: Cerebral autoregulation; Outcome; PRx; Pediatric; Pressure reactivity; Traumatic brain injury.