The Relationship Between Intracranial Pressure and Brain Oxygenation in Children With Severe Traumatic Brain Injury

Neurosurgery, 04/30/2012

The relationship between intracranial pressure (ICP) and PbtO2 appears complex, and several factors likely influence both variables separately and in combination. Although very high ICP is associated with reduced PbtO2, in general, absolute ICP has a poor relationship with PbtO2. Because reduced PbtO2 is independently associated with poor outcome, a better understanding of ICP and PbtO2 management in pediatric traumatic brain injury (TBI) seems to be needed.

Methods

  • The relationship between time-linked hourly and high-frequency ICP and PbtO2 data was examined using correlation, regression, and generalized estimating equations.
  • Thresholds for ICP were examined against reduced PbtO2 using age bands and receiver-operating characteristic curves.

Results

  • Analysis using more than 8300 hourly (n=75) and 1 million high-frequency data points (n=30) demonstrated a weak relationship between ICP and PbtO2 (r=0.05 and r=0.04, respectively).
  • No critical ICP threshold for low PbtO2 was identified.
  • Individual patients revealed a strong relationship between ICP and PbtO2 at specific times, but different relationships were evident over longer periods.

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