Assessment of optimal blood pressure using near-infrared spectrometry in traumatic brain injury patients

Blood pressure control is an important element of intensive care in patients with TBI ensuring adequate cerebral blood flow and oxygenation. One can estimate optimal blood pressure during monitoring of cerebral autoregulation (CA) using various methods. Objective. To compare the optimal blood pressures obtained by invasive (intracranial pressure, ICP) and non-invasive (NIRS) monitoring of cerebral hemodynamics and oxygenation in patients with TBI. Material and methods. We assessed cerebral autoregulation using PRx and COx coefficients. The last ones were calculated using ICM+ software (UK) as correlation coefficients between blood pressure and ICP, blood pressure and cerebral oxygenation (rSO2). Optimal blood pressure implied the best cerebrovascular response and minimum PRx and COx coefficients. ICP was monitored using Codman Microsensor sensors (Codman & Shurtleff Inc., USA), ICP Express Codman intracranial pressure monitoring system (Codman & Shurtleff Inc., USA) and MP60 monitor (Philips Medical Systems, the Netherlands). Cerebral oximetry was recorded using NIRS INVOS 5100 monitor (Covidien LLC, USA). Results. There was significant correlation between optimal (target) mean BPs (R=0.49, R2=0.24, p<0.038). The Bland-Altman analysis revealed good agreement between BPs with a bias of 0.39±7.89 for Cox-based optimal BP and PRx-based BP. Conclusion. Optimal blood pressure based on invasive intracranial pressure monitoring is comparable to blood pressure based on cerebral oximetry (near-infrared spectroscopy). One can estimate Cox-based optimal blood pressure using near-infrared spectroscopy in patients with diffuse traumatic brain injury (Marshall grade I—II).