The Effects of Posture on Cerebral Blood Flow Velocity During the Acute Phase of Stroke
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 32
- 试验地点
- 1
- 主要终点
- Change in cerebral blood flow velocity (cm/s^1)
研究概览
简要总结
After stroke, blood vessels in the brain can become damaged, and the brain's ability to control blood flow can be impaired. The brain therefore may be less able to maintain a healthy level of blood flow during challenges such as changes in posture. Studies have shown that sitting upright early after stroke can cause brain blood flow to reduce. However, no studies have investigated how standing up affects blood flow to the brain. In this study, transcranial Doppler ultrasound will be used to assess how cerebral blood flow velocity changes when acute stroke patients stand up.
详细描述
Introduction
Clinical guidelines recommend that some stroke survivors should engage in out-of-bed sitting, standing and walking activities early after stroke. Studies have found that compared to lying flat, sitting upright reduces brain blood flow early after stroke. However, no research has been done to find out how standing affects brain blood flow early after stroke. The transition from sitting to standing causes blood to move away from the head toward the legs, which can lower blood pressure and brain blood flow. In healthy individuals, blood vessels in the brain respond to reduced blood flow and blood pressure by dilating (widening), diverting more blood to the brain. After a stroke, the blood vessels in the brain can become damaged and their ability to control blood flow can be impaired. This raises the concern that standing early after a stroke could cause brain blood flow to drop too low which may worsen the brain injury. A recent large-scale trial reported that starting rehabilitation activities (including standing) earlier (18.5 hours vs 22.4 hours after stroke) resulted in poorer recovery of physical function measured three months after stroke. Lowered brain blood flow, caused by standing, may have contributed to this negative outcome. However, the effects of standing on brain blood flow early after stroke have not yet been investigated. This study will investigate the effects of standing on cerebral blood flow velocity, measured using transcranial Doppler ultrasound, within 1-7 days of stroke onset.
Participants
People with acute ischaemic or haemorrhagic stroke admitted to the Royal Hallamshire Hospital (Sheffield, England) will be recruited to this study after providing informed consent.
Mobilisation Protocol
研究设计
- 研究类型
- Observational
- 观察模型
- Case Only
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adult (age ≥18 years) patients diagnosed with any subtype of stroke (first or recurrent).
- •Medically stable, assessed by a stroke physician.
- •Able to be enrolled between within 7 days of stroke symptom onset.
- •Able to sit independently.
- •Able to stand with or without assistance.
- •Sufficient English language comprehension and cognitive ability to understand the study protocol, give informed consent and follow instructions.
排除标准
- •Autonomic nervous system disorder causing haemodynamic instability e.g. pure autonomic failure, Parkinson's disease, multiple system atrophy and Shy-Drager syndrome
- •Lower-limb pain when standing.
- •Restricted range of motion due to spasticity or contracture impairing ability to stand.
- •Orthopaedic impairment (e.g. bone fracture or ligament rupture) preventing prevent full weight bearing activities.
- •Resting systolic blood pressure ≤100 mmHg or ≥180 mmHg.
- •Resting diastolic blood pressure ≤50 mmHg or ≥120 mmHg.
- •Significant tachycardia ≥120 beats per minute at rest.
- •Significant bradycardia ≤40 beats per minute at rest.
- •Peripheral oxygen saturation ≤85% without use of supplementary oxygen.
- •Life expectancy <6 months (terminal illness).
- •Currently participating in another clinical trial that is likely to affect outcome measures (e.g. experimental drug that affects blood pressure or blood vessel tone).
- •Likely to be discharged from hospital or repatriated within 48 hours of stroke onset.
结局指标
主要结局
Change in cerebral blood flow velocity (cm/s^1)
时间窗: Day 1 (measured over a 14-minute period)
Absolute change in bilateral mean middle cerebral artery velocity (cm/s\^1)
次要结局
- Disability(Day 1 (at study enrollment) & 3 months post-stroke)
- Adverse events(3 months post-stroke)
- Functional independence(Day 1 (at study enrollment) & 3 months post-stroke)
- Change in cerebral blood flow velocity (%)(Day 1 (measured over a 14-minute period))
- Change in blood pressure(Day 1 (measured over a 14-minute period))
- Change in heart rate(Day 1 (measured over a 14-minute period))
研究者
Simon Nichols
Senior Research Fellow
Sheffield Hallam University