OBJECTIVE. Cerebrovascular vasomotor reactivity reflects changes in smooth muscle tone in the arterial wall in response to changes in transmural pressu

Objectives: We have sought to develop an automated methodology for the continuous updating of optimal cerebral perfusion pressure (CPP_opt) for patients after severe traumatic head injury, using continuous monitoring of cerebrovascular pressure reactivity. We then validated the CPP_opt algorithm by determining the association between outcome and the deviation of actual CPP from CPP_opt. Design: Retrospective analysis of prospectively collected data. Setting: Neurosciences critical care unit of a university hospital. Patients: A total of 327 traumatic head-injury patients admitted between 2003 and 2009 with continuous monitoring of arterial blood pressure and intracranial pressure. Measurements and Main Results: Arterial blood pressure, intracranial pressure, and CPP were continuously recorded, and pressure reactivity index was calculated online. Outcome was assessed at 6 months. An automated curve fitting method was applied to determine CPP at the minimum value for pressure reactivity index (CPP_opt). A time trend of CPP_opt was created using a moving 4-hr window, updated every minute. Identification of CPP_opt was, on average, feasible during 55% of the whole recording period. Patient outcome correlated with the continuously updated difference between median CPP and CPP_opt (chi-square = 45, p < .001; outcome dichotomized into fatal and nonfatal). Mortality was associated with relative “hypoperfusion” (CPP < CPP_opt), severe disability with “hyperperfusion” (CPP > CPP_opt), and favorable outcome was associated with smaller deviations of CPP from the individualized CPP_opt. While deviations from global target CPP values of 60 mm Hg and 70 mm Hg were also related to outcome, these relationships were less robust. Conclusions: Real-time CPP_opt could be identified during the recording time of majority of the patients. Patients with a median CPP close to CPP_opt were more likely to have a favorable outcome than those in whom median CPP was widely different from CPP_opt. Deviations from individualized CPP_opt were more predictive of outcome than deviations from a common target CPP. CPP management to optimize cerebrovascular pressure reactivity should be the subject of future clinical trial in severe traumatic head-injury patients.