The Prediction of Intracranial Pressure and Clinical Outcome by Transcranial Doppler in Neurocritical Patients

Transcranial Doppler (TCD) and Transcranial color-coded duplex sonography (TCCS) play an important part in neurocritical monitoring systems. Currently there are studies using flow velocities and pulsatility index (PI) to predict intracranial pressure (ICP) and clinical outcome. But the use of B-mode in such prediction is not yet investigated. The purposes of this study are to establish the correlation among clinical data, CT findings and information collected by TCCS, and to predict ICP and neurological outcome using such information. The focus would be on 3rd ventricle size, midline shift and anteroposterior-transverse ration of midbrain (midbrain index) obtained by B-mode of TCCS. This study is a prospective clinical study targeting on 30 neurocritical patients admitted to intensive care units in one year. The timing of performance of TCCS will be (1) within 6 hours after admission, (2) within 6 hours after each CT examination, and (3) when ICP is higher than 20 mmHg for more than 5 minutes. Glasgow coma scale (GCS), heart rate, blood pressure (systolic, diastolic, and mean), body temperature, central venous pressure (CVP), brain temperature, ICP, cerebral perfusion pressure (CPP), mean velocity (MV) of bilateral middle cerebral arteries (MCAs), PI, midline shift, 3rd ventricular dimension, anteroposterior to transverse ratio of midbrain (midbrain index, MI) are recorded. The latter three parameters are also obtained from CT scans, and compared with those obtained from TCCS. Outcome is evaluated with extended Glasgow outcome scale (GOSE), and analyzed with previous records. This study is going to prove that TCCS is a safe, convenient, real-time and cheap tool in clinical care for neurocritical patients. It also provides prediction of ICP and clinical outcome.