Transcranial Doppler to detect early abnormalities in cerebral hemodynamics following traumatic brain injury in adult patients

Abstract

Background Transcranial Doppler (TCD) can be a valuable tool in detecting early changes in cerebral blood flow (CBF) velocities following traumatic brain injury (TBI). We designed this prospective observational study to screen for early abnormalities in CBF following TBI using TCD and to evaluate its ability to predict the patients’ outcome. Patients and methods The study was carried out on 66 adult patients admitted to the ICU with TBI. TCD was performed on admission by insonating the middle cerebral arteries and extracranial internal carotid arteries, and flow velocities were recorded, and pulsatility index (PI) and Lindegaard ratio were calculated. End-diastolic velocity (EDV) less than 25 cm/s and PI more than 1.3 were considered abnormal. The patient outcome was evaluated at discharge from the hospital using the Glasgow Outcome Scale. Results Admission TCD revealed that EDV less than 25 cm/s was present in 11.1% of the patients with mild-to-moderate TBI [Glasgow Coma Score (GCS)>8] and in 46.7% of the patients with severe TBI (GCS≤8). PI more than 1.3 was present in 16.7% of the patients with GCS more than 8 and in 46.7% of the patients with GCS less than or equal to 8. The incidence of vasospasm was highest on the fifth day after trauma as it was detected in 16.7% of the patients with GCS more than 8 and in 40% of the patients with GCS less than or equal to 8. The logistic regression analysis of outcome predictors showed that the initial PI more than 1.3 had 91% sensitivity and 89% specificity and EDV less than 25 cm/s had 88% specificity and sensitivity 85% in predicting poor outcome; meanwhile, cerebral vasospasm had 84% sensitivity and 75% specificity in poor outcome prediction. Conclusion Early abnormal CBF velocity detected by TCD following TBI can predict poor outcome at discharge from the hospital.