gms | German Medical Science

Objective: Acute brain insults might produce a raise of ICP. As important as keeping ICP levels below thresholds (which?) is maintaining a CPP level, that maximizes chances for sufficient brain perfusion (CPPopt). CPPopt is completely unknown unless determined. An important recent advancement in neuro-intensive care was the recognition that cerebrovascular autoregulation (AR), being a major mechanism regulating cerebral blood flow, can be determined from correlating ICP and blood-pressure (PRx: pressure-reactivity-index). PRx can be used to identify the individual CPPopt at a specific time. We report our experience with PRx and CPPopt in pediatric neurocritical care.

Methods: 17 children with severe TBI (mean GCS 5) and 11 children with status post resuscitation underwent computerized ICP and ABP monitoring with ICM+ software to determine CPP, PRx and CPPopt continuously. PRx and CPPopt were used to guide ICP and APB, aiming to keep patients at CPPopt. If ICP couldn't be controlled conservatively decompressive craniectomy but never barbiturates were used.

Results: In all patients PRx could be determined and, provided AR was intact or recovering, CPPopt calculated. In early fatal cases AR was absent. In surviving cases, when dichotomized to favorable/unfavorable outcome (50% each), no significant difference existed for overall ICP, CPP and PRx. However, time with impaired AR (PRx >0.2) was significantly longer in unfavorable outcome patients in both groups (64h vs. 6h for TBI and 59h vs. 10h in post. resuscitation, p<0.01). Continuously impaired AR of ≥ 24h was associated with unfavorable outcome in all cases.

Conclusion: More important than just controlling ICP is using the ICP-signal to guide ABP management, thus AR and to bring and maintain patients at CPPopt. Duration of dysautoregulation seems to be critically associated to unfavorable outcome. Thus, optimization of autoregulation is a key principle to improve outcome in pediatric neurointensive care.