Background: The aim of this study was to evaluate the usefulness of early Transcranial Doppler (TCD) in guiding initial resuscitation of traumatic and non-traumatic comatose patients before diagnostic imaging and invasive neurologic monitoring.
Methods: This was a prospective, interventional study and included patients in coma, before performing diagnostic imaging. A TCD was performed as soon as possible upon admission. Diastolic velocity (DV) <20 cm/s and Pulsatility Index (PI) >1.4 at both middle cerebral arteries were considered abnormal and specific therapy was started with fluid expansion with 2 L 0.9% saline solution, followed by norepinephrine infusion to increase MAP above 110 mmHg. An increment in DV >20 cm/s was considered as a good response.
Results: Twenty-eight patients were included, 9 had normal TCD and 19 (68%) had abnormal TCD values. Mean values pre- and post-treatment were: MAP 84 ± 16/121 ± 9 mmHg; PI 2.26 ± 0.52/1.28 ± 0.47; DV 13 ± 7/33 ± 18 cm/s (P<0.0001 for all values); 13 patients (68%) were responders. Global mortality was 46 %. We find that the presence of oscillating flow, systolic peak or DV <20 cm/s after treatment, were associated with brain death in 100% of cases. Presence of a normal TCD was associated with no mortality.
Conclusion: Our study suggests that early TCD is feasible to evaluate qualitative information about cerebral perfusion in comatose patients while they are waiting for diagnostic imaging studies.