gms | German Medical Science

Objective: It could be shown in severe traumatic brain injury (TBI) in adults, that the functional status of cerebrovascular autoregulation (AR), determined by the pressure reactivity index (PRx), correlates to outcome. We investigated PRx and its correlation to outcome in infant and pediatric TBI.

Method: Seventeen patients (median 3.2yrs, range 1d-14yrs) with severe TBI (GCS at presentation <9) underwent longtime computerized ICP and MAP monitoring using dedicated software to determine CPP and PRx continuously. Outcome was determined at discharge and at follow-up at 6 months using the Glasgow Outcome Scale.

Results: Median monitoring time was 152h (range 22-355h). 9 patients underwent decompressive craniectomy to control ICP. Favorable outcome (GOS 4 and 5) was reached in 8, unfavorable outcome (GOS 1-3) in 9 patients. When dichotomized to outcome no significant difference was found to overall ICP, CPP and PRx. But mean overall PRx correlated well to outcome (r=-0.70, p=0.001) and tended to be lower for GOS 4 and 5 (-0.10) than GOS 1-3 (0.16). The relative duration of impaired AR (assuming threshold PRx ≥ 0.2) was longer for patients with unfavorable outcome (38 vs. 6 % of monitoring time) (p=0.057). Continuously impaired AR of 24 hours or more was associated with unfavorable outcome in 100% of the patients (n=8).

Conclusions: 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 furthermore seems to be the most promising candidate parameter to guide the adjustment of CPP during ICU treatment, aiming at an improvement of cerebrovascular autoregulatory ability to ensure the best possible CBF during the critical phase of increased vulnerability to secondary injury following traumatic brain injury (CPPopt concept).