Blood Pressure Management in Acute Stroke Victor C. Urrutia, MD * , Robert J. Wityk, MD Cerebrovascular Division, Department of Neurology, Johns Hopkins University School of Medicine, Phipps 126, 600 North Wolfe Street, Baltimore, MD 21287, USA The optimal management of arterial blood pressure in the setting of an acute stroke has not been defined [1,2]. Many reviews have been published on this topic in the past few years, but definitive evidence from clinical trials continues to be lacking [3–7]. This situation is complicated further because stroke is a heterogeneous disease. The best management of arterial blood pressure may be different depending on the type of stroke (ischemic or hem- orrhagic) and among the subtypes of ischemic or hemorrhagic stroke [1,8]. This article reviews the relationship between arterial blood pressure and the pathophysiology specific to ischemic stroke, primary intracerebral hemor- rhage (ICH), and aneurysmal subarachnoid hemorrhage (SAH), elaborating on the concept of ischemic penumbra and the role of cerebral autoregula- tion. The article also examines the impact of blood pressure and its manage- ment on outcome. Finally, an agenda for research in this field is outlined. Cerebral autoregulation Cerebral autoregulation is the mechanism by which cerebral blood flow (CBF) remains constant across a wide range of cerebral perfusion pressures (CPP). This is achieved by reflex vasoconstriction or vasodilation of the cerebral arterioles in response to changes in perfusion pressure. CPP is defined by the following relationship: CPP ¼ MAP  ICP Where MAP is mean arterial pressure, and ICP is intracranial pressure. If ICP is constant and not elevated, MAP and CPP are proportional; they can be used interchangeably when talking about autoregulation. * Corresponding author. E-mail address: vurruti1@jhmi.edu (V.C. Urrutia). 0749-0704/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.ccc.2006.08.002 criticalcare.theclinics.com Crit Care Clin 22 (2007) 695–711