THE EFFICACY AND SAFETY OF USING PHENYLEPHRINE TO OPTIMIZE CEREBRAL PERFUSION IN DELAYED NEURO-INTERVENTION OF ACUTE ISCHEMIC STROKE

Abstract

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Permissive hypertension (HTN) in the management of acute ischemic stroke (AIS) is not novel but a more recent approach considers the use of vasopressors to optimize cerebral perfusion pressure in the normotensive patient. CASE PRESENTATION: A 67-year-old female, active smoker with no medical history, presented with difficulty speaking for 6 hours. Exam revealed expressive aphasia with no other neurologic deficits. CT angiogram head showed abrupt cut-off of the distal M1 segment extending to the middle cerebral artery (MCA) bifurcation and proximal M2 vessels consistent with thromboembolism. Labs including cardiac enzymes were unremarkable. Cerebral angiogram showed high-grade sub occlusive stenosis of cervical left internal cerebral artery (ICA) and left MCA. She was admitted to the intensive care unit and placed on aspirin and clopidogrel. A systolic blood pressure (SBP) goal of 160-180mmHg was achieved using normal saline and phenylephrine (PE) infusions. 72 hours later she underwent successful percutaneous transluminal carotid artery angioplasty and stenting of the left ICA stenosis with subsequent complete resolution of her symptoms. PE was discontinued with new goal of SBP 100-120mmHg. Three days later she had acute onset chest pain. ST depressions in anterolateral leads on electrocardiogram and elevated cardiac enzymes prompted coronary angiography, which showed triple vessel disease requiring coronary artery bypass grafting. DISCUSSION: A U-shaped relationship exists regarding morbidity and mortality in SBP control in AIS. Elevated SBP increases risk of brain edema and hemorrhagic conversion while low pressures cause decreased central perfusion pressure leading to decreased collateral circulation to ischemic areas. In a 2001 pilot study using PE in patients with AIS, beyond the window of systemic thrombolysis, 54% of patients had improved NIH stroke scale (NIHSS) after achieving target SBP (160 mmHg or increase by 20% of admission SBP without exceeding 200 mmHg); no systemic or neurologic complications were reported.(1) A randomized trial (RT) utilizing PE to target an elevated SBP showed a short-term improvement in the NIHSS, cognitive score, and volume of hypoperfused tissue, when compared to the control group, in individuals with subacute and AIS.(2) In a multicenter RT of patients with noncardioembolic AIS, ineligible for revascularization therapy, PE was used to increase SBP up to 200 mmHg. 88.2% of patients in the intervention group exhibited improvements in NIHSS scores of ≥2 points; safety outcomes did not significantly differ between groups.(3) Our patient had complete resolution of neurologic symptoms after PE use and neuro-intervention, which preceded a cardiac event. CONCLUSIONS: While evidence exists to support the efficacy and safety of PE for SBP augmentation in the setting of AIS, larger studies with emphasis on safety are needed, as currently no guidelines exist. Reference #1: Rordorf G., Koroshetz W.J., Ezzeddine M.A., Segal A.Z., Buonanno F.S. A pilot study of drug-induced hypertension for treatment of acute stroke. Neurology. 2001 May 8;56(9):1210-3. doi:10.1212/wnl.56.9.1210 Reference #2: Hillis A.E., Ulatowski J.A., Barker P.B., et al. A pilot randomized trial of induced blood pressure elevation: effects on function and focal perfusion in acute and sub acute stroke. Cerebrovasc Dis. 2003;16(3):236-246. doi: 10.1159/000071122 Reference #3: Bang O.Y., Chung J.W., Kim S.K., et al. Therapeutic-induced hypertension in patients with noncardioembolic acute stroke. Neurology. 2019 Nov 19;93(21):e1955-e1963. Epub 2019 Oct 23. doi: 10.1212/WNL.0000000000008520. DISCLOSURES: No relevant relationships by Kyle Foster, source=Web Response No relevant relationships by Nisha Gandhi, source=Web Response No relevant relationships by Matthew Tavares, source=Web Response