Feasibility of a Continuous Computerized Monitoring of Cerebral Autoregulation in Neurointensive Care

Abstract

In order to monitor cerebral autoregulation status, a software package was developed to calculate a cerebral autoregulation index (pressure reactivity index, PRx). The aim of this study is to evaluate whether the application of this methodology is feasible and useful in the clinical setting. Prospective observational study. NeuroIntensive Care Unit (NICU) of a university-affiliated teaching hospital. Twenty-six consecutive patients admitted to NICU requiring intracranial pressure (ICP) and invasive arterial pressure (AP) monitoring. Patient's data were collected for a total of 902 h. Mean PRx was calculated utilizing 2 h time window. CPP-PRx distribution graphs were calculated from CPP of 20 to 110 mmHg using 10 mmHg intervals. Autoregulation was preserved in 18% observations (83/451) and deranged in 49% observations (220/451). In 33% observations (148/451), autoregulation could not be clearly defined (0 < PRx < 0.2). Even if no clinical protocol was developed, autoregulation status information inserted in clinical decision pathway influenced clinical management. Mean CPP, calculated at maximum and minimum ICP every 2 h interval, resulted different between groups with good and poor reactivity (67 +/- 17.6 and 85 +/- 20.0 mmHg, respectively, for autoregulating observations and 60 +/- 19.1 and 67 +/- 19.4 mmHg, respectively, for nonautoregulating observations, P < 0.001, independent samples t-test). PRx values were normally distributed. Our study demonstrates that a daily bedside measure of cerebral autoregulation is feasible. PRx values can support clinicians in the identification of a targeted CPP in patients suffering from different intracranial pathologies and requiring an intensive monitoring.