Continuous Monitoring of Cerebrovascular Reactivity Using Pulse Waveform of Intracranial Pressure

Guidelines for the management of traumatic brain injury (TBI) call for the development of accurate methods for assessment of the relationship between cerebral perfusion pressure (CPP) and cerebral autoregulation and to determine the influence of quantitative indices of pressure autoregulation on outcome. We investigated the relationship between slow fluctuations of arterial blood pressure (ABP) and intracranial pressure (ICP) pulse amplitude (an index called PAx) using a moving correlation technique to reflect the state of cerebral vasoreactivity and compared it to the index of pressure reactivity (PRx) as a moving correlation coefficient between averaged values of ABP and ICP. A retrospective analysis of prospective 327 TBI patients (admitted on neurocritical care unit of a university hospital in the period 2003-2009) with continuous ABP and ICP monitoring. PAx was worse in patients who died compared to those who survived (-0.04 +/- A 0.15 vs. -0.16 +/- A 0.15, chi(2) = 28, p