Physiologic Effects of RBC Storage in Chronic Transfusion Recipients: Vasoreactivity, Exercise Capacity, and Oxygen Consumption
试验速览
- 阶段
- 4 期
- 状态
- 终止
- 入组人数
- 15
- 试验地点
- 2
- 主要终点
- Change in Reactive Hyperemic Index (RHI)
研究概览
简要总结
The purpose of this study is to determine how red blood cell transfusions, particularly the length of storage time of units of packed red blood cells, affects the cardiovascular function in patients receiving transfusions. This study will also determine the most ideal way of storing and processing blood, and assess how transfusion affects a person's ability to exercise and how their blood vessels relax and contract.
详细描述
The purpose of this study is determine red blood cell transfusion, particularly the length of storage time of units of packed red blood cells, affects cardiovascular function in patients receiving transfusions. Transfusion of red blood cells is often used clinically in patients with low red blood cell counts in order to prevent disease progression and death. Recent studies suggest that the use of "aged" versus "fresh" red blood cells is associated with worse clinical outcomes, but there is no clear understanding on how this happens. The investigators want to determine the most ideal way of storing and processing blood, and learn how transfusion affects the ability to exercise in the study subjects and assess the relaxation and contraction of the blood vessels.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- Double (Participant, Outcomes Assessor)
入排标准
- 年龄范围
- 21 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Subjects with any condition resulting in transfusion-dependent anemia
排除标准
- •Age <21 or >80 years
- •Pregnancy
- •Acute infection in previous 4 weeks
- •Active substance abuse within the past year
- •Inability to give informed consent
- •Inability to return for follow-up
- •The presence of alloantibodies that would limit the blood bank's ability to obtain correctly aged red blood cell (RBC) units
结局指标
主要结局
Change in Reactive Hyperemic Index (RHI)
时间窗: Baseline (prior to transfusion), Day 1 (first post-transfusion day)
Reactive Hyperemia Index (RHI) will be measured using Pulsatile Arterial Tonometry (PAT). Baseline blood pressure of both hands is measured and PAT probes are placed one on each hand at the same finger (fingers 2, 3 or 4). Following an equilibration period of 10 minutes, the blood pressure cuff will be inflated to 60 mmHg above systolic pressure for 5 minutes followed by deflation of the cuff and the pulsatile recordings from both study and control fingers will be measured. RHI will be calculated from the ratio of the digital pulse volume during reactive hyperemia (following cuff deflation) and baseline. A higher RHI indicates better nitric oxide-dependent endothelial function.
Change in Flow-mediated Vasodilation (FMD)
时间窗: Baseline (prior to transfusion), Day 1 (first post-transfusion day)
Brachial artery flow-mediated dilation (FMD) will be performed by using ultrasonography. The brachial artery of the non-dominant arm will be imaged using a high-resolution 13 MHz ultrasound transducer. A blood pressure cuff on the forearm will be inflated to supra-systolic pressures to produce 5 minutes of ischemia. After cuff deflation, imaging of the brachial artery will be performed continuously for the next 120 seconds and the flow-mediated dilation will be calculated. Change in FMD is the percent change in the diameter of the brachial artery from baseline (prior to transfusion) to Day 1 (first post-transfusion day). A higher FMD indicates better nitric oxide-dependent endothelial function.
次要结局
- Respiratory Exchange Ratio (RER):(Day 1 (first post-transfusion day))
- Peak VO2 Lean(Day 1 (first post-transfusion day))
- Maximal Oxygen Uptake (VO2Max)(Day 1 (first post-transfusion day))
- O2 Pulse(Day 1 (first post-transfusion day))
- Change in Oxidative Stress Markers(Baseline (prior to transfusion), Day 1 (first post-transfusion day))
- Change in Levels of IL-6(Baseline (prior to transfusion), Day 1 (first post-transfusion day))
- Change in Levels of IL-2(Baseline (prior to transfusion), Day 1 (first post-transfusion day))
- Change in Levels of Nitric Oxide Metabolites(Baseline (prior to transfusion), Day 1 (first post-transfusion day))
- Change in High-sensitivity C-reactive Protein (hsCRP)hsCRP(Baseline (prior to transfusion), Day 1 (first post-transfusion day))
研究者
Arshed A. Quyyumi
Professor
Emory University