Use of Transcranial Doppler in Patients with Severe Traumatic Brain Injuries.

Severe traumatic brain injuries (TBI) are associated with a high rate of mortality and disability. Transcranial Doppler (TCD) sonography permits a noninvasive measurement of cerebral blood flow. The purpose of this study is to determine the usefulness of TCD in patients with severe TBI. TCD was performed, from April 2008 to April 2013, on 255 patients with severe TBI, defined as a Glasgow Coma Scale score of ≤8 on admission. TCD was performed on hospital days 1, 2, 3, and 7. Hypoperfusion was defined by having two out of three of the following: 1) mean velocity (Vm) of the middle cerebral artery <35 cm/sec, 2) diastolic velocity (Vd) of the middle cerebral artery <20 cm/sec, or 3) pulsatility index (PI) of >1.4. Vasospasm was defined by the following: Vm of the middle cerebral artery >120 cm/sec and/or a Lindegaard index (LI) >3. One hundred fourteen (45%) had normal measurements. Of these, 92 (80.7%) had a good outcome, 6 (5.3%) had moderate disability, and 16 (14%) died, 4 from brain death. Seventy-two patients (28%) had hypoperfusion and 71 (98.6%) died, 65 from brain death, and 1 patient survived with moderate disability. Sixty-nine patients (27%) had vasospasm, 31 (44.9%) had a good outcome, 16 (23.2%) had severe disability, and 22 (31.9%) died, 13 from brain death. The vasospasm was detected on hospital day 1 in 8 patients, on day 2 in 23 patients, on day 3 in 22 patients, and on day 7 in 16 patients. Patients with normal measurements can be expected to survive. Patients with hypoperfusion have a poor prognosis. Patients with vasospasm have a high incidence of mortality and severe disability. TCD is useful in determining early prognosis.