To compare brain perfusion-computed tomography (CT) results with invasive cerebral perfusion pressure (CPP) monitoring in severe head trauma patients.Design:
Prospective cohort study.Setting:
Emergency room and surgical intensive care unit of our hospital.Patients:
Sixty-one severe head trauma patients.Interventions:
We prospectively collected 103 perfusion-CT examinations with simultaneous measurement of mean arterial pressure and intracranial pressure, affording calculation of CPP. The statistical relationship between perfusion-CT results and the corresponding CPP values was evaluated using Wilcoxon (Mann-Whitney) and generalized F-tests. The functional outcome of the 61 patients was evaluated 3 months after trauma on the basis of the Glasgow Outcome Scale score and compared between groups using Fisher’s exact tests.Measurements and Main Results:
Perfusion-CT enabled us to distinguish between two groups of patients. Within each group, a significant correlation (p < .001) between the CPP values and the corresponding perfusion-CT results was demonstrated. There was also a significant correlation (p < .001) between the CPP values and the extent of the abnormal perfusion-CT areas (R2 up to .817).Measurements and Main Results:
The first group was characterized by a weak dependence of perfusion-CT results on the corresponding CPP values (low slope) and the second group by a strong dependence (steep slope). These groups were interpreted as having preserved (or pseudo) and impaired cerebral vascular autoregulation, respectively. The functional outcome was better in the second group of patients.Conclusions:
Intermittent perfusion-CT measurements plus continuous CPP measurement provide more information than continuous CPP alone. Perfusion-CT gives unique information regarding regional heterogeneity of brain perfusion. It might allow clinicians to distinguish between patients with preserved auto-regulation (or pseudoautoregulation) and those with impaired autoregulation and could therefore guide interpretation of CPP measurements and therapy.