Zero Degree Head Positioning in Hyperacute Large Artery Ischemic Stroke

Overview

Placing the head of bed (HOB) at 0-degrees has been shown in small studies to improve blood flow to the brain in patients with ischemic stroke caused by large artery occlusions, thereby reducing stroke symptom worsening. This simple yet potentially impactful intervention has yet to be tested in a large clinical trial in hyperacute large artery ischemic stroke patients, but may provide nurses with a powerful contribution to acute stroke care that is capable of preventing worsening of stroke symptoms and promoting stabilization. Because stroke is the leading cause of preventable long-term disability in adults, this study may show that simple methods such as 0-degree HOB positioning should be considered one of the very first actions taken in the emergent management of acute ischemic stroke patients.

Positioning of the patient during hyperacute ischemic stroke (AIS) treatment is an important, yet understudied aspect of nursing care that could impact the course of treatment and clinical outcome. Since 1968, clinical symptom worsening in AIS patients has been documented with the head of bed (HOB) elevated to 30 degrees or higher, while clinical improvement or symptom stability has been noted with zero degree HOB positioning. Mechanisms for zero degree HOB clinical improvement include favorable gravitational blood flow conditions and recruitment of collateral blood channels, while in the case of treatment with clot-busting medications, increased blood flow may allow more medication to reach occluded arteries facilitating clot breakdown. Despite this, there is currently divide within the clinical community about what position is best for patients, although it has been argued that zero degree head positioning should be among the first steps taken to improve blood flow to the brain and prevent stroke symptom worsening. The investigators have shown that elevated ICP is absent in early AIS, and that pneumonia is rare using these piloted methods. However, no large clinical trial has examined efficacy and safety of zero degree HOB positioning within hyperacute large vessel occlusion (LVO) ischemic stroke patients with potentially viable brain tissue, leaving the acute stroke community confused as to what constitutes best practice. ZODIAC is a prospective randomized open blinded endpoint (PROBE) clinical trial of head positioning to determine if zero degree HOB positioning during the early phase of hyperacute LVO ischemic stroke management prevents neurological symptom worsening. Mechanical thrombectomy (MT) eligible patients (n=182) will be randomized to one of two groups: 1) Zero degree HOB positioning; or, 2) thirty degree HOB positioning. The hypothesis is that optimal HOB position can be determined by early neurological symptom worsening during the intervention (Aim 1) prior to initiation of the thrombectomy procedure, and the investigators propose that real-time deterioration may be a surrogate measure for decreased downstream perfusion, potentially impacting viability of brain at risk for infarction. Aim 2 will confirm that use of zero degree HOB positioning for AIS is safe. Use of this nursing measure holds significant promise as an innovative adjunct method to improve AIS symptoms, and ultimately reduce disability.