Quantification of secondary CPP insult severity in paediatric head injured patients using a pressure-time index

Summary

This paper describes and validates a new Cumulative Pressure-Time Index (CPT) which takes into account both duration and degree of cerebral perfusion pressure (CPP) derangement and determines critical thresholds for CPP, in a paediatric head injury dataset.

Sixty-six head-injured children, with invasive minute-to-minute intracranial pressure (ICP) and blood pressure monitoring, had their pre-set CPP derangement episodes (outside the normal range) identified in three childhood age-bands (2–6, 7–10, and 11–16 years) and global outcome assessed at six months post injury.

The new cumulative pressure-time index more accurately predicted outcome than previously used summary measures and by varying the threshold CPP values, it was found that these physiological threshold values (≤48, ≤52 and ≤56 mmHg for 2–6, 7–10, and 11–16 years respectively) best predicted brain insult in terms of subsequent mortality and morbidity.