Abstract TP530: Transcranial Doppler Blood Velocities Kinetics During Treatment for Delayed Cerebral Ischemia in Patients With Subrachnoid Hemorrhage

Abstract

The role of Transcranial Doppler (TCD) in monitoring patients with subarachnoid hemorrhage (SAH) for delayed cerebral ischemia (DCI) is well established. However, the response and kinetics of TCD blood flow velocities (BFV) to treatment of DCI has been scarcely investigated. We assessed the hypothesis that TCD BFV decrease progressively after treatment of DCI with vasopressors or inotropics. Methods: All patients with SAH admitted to a tertiary hospital neurocritical unit were evaluated with daily TCD exams for monitoring for DCI from June 2016 to June 2018. DCI was defined as the development of new focal neurological signs and/or deterioration in level of consciousness, lasting for more than 1 h, or the appearance of new infarctions on neuroimaging. Patients who developed DCI and were treated with vasopressors or inotropics were prospectively included in this study. TCD exams were performed immediately before (t0), 1 hour (t1) and 2 hours after (t2) the initiation of therapy for DCI by the same neurosonologist. Clinical and physiological data before and during exams were recorded. Results: 27 DCI treatments with either norepinephrine (n=12) or milrinone (n=15) in 21 patients were monitored. Patients were mainly females (88.9%, mean age 50.41+/- 12.52 year-old) with low grade clinical SAH (44.4% World Federation of Neurosurgeons Scale 1 and 2) but with high modified Fisher scores (81.1% with modified Fisher score of 3 and 4). DCI occurred 11.6+/- 3.4 days from the initial bleeding. Cerebral BFV significantly dropped after treatment (t0=158.08 +/- 42.84 cm/s; t1=146.71+/- 42.19 cm/s; t2=136.46+/-44.43 cm/s, p<0.01). There was also a significant drop in the National Institutes of Health stroke scale scores after therapy (t0= 13 [ 8, 19]; t1 12 [6, 19]; t2 9 [6, 19], p< 0.01). Patients treated with milrinone had a greater decline in cerebral BFV compared to those treated with norepinephrine (milrinone: t0 203.14+/- 49.41 cm/s; t1 183.14 +/-35.44 cm/s; t2= 167.86 +/- 37.55 cm/s, p=0.04 versus norepinephrine t0=156 +/- 27.45 cm/s; t1=164.58 +/- 40.48 cm/s; t2=159.0 +/- 48.24 cm/s, p=0.67). Conclusion: TCD BFV decrease progressively with hemodynamic therapy for DCI. Use of milrinone was associated with a greater decline in BFV when compared to norepinephrine.