Clinical value of non-invasive monitoring of cerebral hemodynamics for evaluating intracranial pressure and cerebral perfusion pressure in patients with moderate to severe traumatic brain injury

Objective: To explore the clinical value of non-invasive monitoring of cerebral hemodynamics for evaluating intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in patients with moderate to severe traumatic brain injury (TBI). Methods: Transcranial Doppler (TCD) was employed to detect the hemodynamics of bilateral middle cerebral arteries, including systolic blood flow velocity (Vp), diastolic blood flow velocity (Vd), average flow velocity (Vm), pulsatility index ( PI) and resistance index (RI) in 52 patients with moderate to severe TBI. At the same time, the CPP, ICP and mean arterial blood pressure (MABP) were monitored. The correlations between hemodynamics and MABP, ICP as well as CPP were analyzed. Results: The PI and RI were positively related to the ICP (r=0.881, P<0.0001; r=0.789, P<0.0001). Multiple stepwise regression analysis showed PI was closely associated with ICP (ICP=-8.593+24.295PI; t=13.216, P<0.0001) and significant correlation was also found between CPP and PI as well as MABP (CPP=15.596-22.886PI+0.910MABP; F= 76.597, P<0.0001). Conclusion: Non-invasive monitoring of cerebral hemodynamics by TCD can reflect the real time changes in the ICP and CPP and may be used as an effective tool to monitor the ICP and CPP. This method is non-invasive, safe, cheap, repeatable and applicable in clinical practice.