The Effect of Blood Pressure on Cerebral Perfusion During Vascular Surgery
The Effect of Blood Pressure on Cerebral Perfusion and Oxygenation During Vascular Surgery
研究概览
详细说明
Background: Induction of anesthesia reduces mean arterial pressure (MAP) and cerebral blood flow is normally considered to be maintained by cerebral autoregulation despite changes in MAP between 60 - 150 mmHg and standard of care during anesthesia is to maintain MAP above 60 mmHg. Vascular surgical patients are often elderly with hypertension and atherosclerotic manifestations that may impair cerebral autoregulation of importance for anesthesia-induced reduction in blood pressure.
Objective: To assess the effect of MAP for preservation of cerebral blood flow and oxygenation during vascular surgery.
Hypothesis: The primary hypothesis is that during general anesthesia in vascular surgical patients, cerebral blood flow velocity and oxygenation is higher with MAP maintained at 80-90 mmHg, compared with a MAP maintained at a minimum of 60 mmHg.
MAP is controlled in both groups using continuous infusion of phenylephrine. Phenylephrine is used as a tool in order to assess the effect of MAP on the cerebral circulation. In both groups, central blood volume is optimized by infusion of lactated Ringer´s solution using a goal directed fluid therapy following induction of anaesthesia and before commencement of phenylephrine infusion.
Trial size: The investigators will include 40 participants (2 x 20) in order to detect or reject a 20% difference in middle cerebral artery velocity with a type I error risk of 5% and a type II error risk of 20% (power at 80%). Interim analysis will be conducted after inclusion of 20 patients (2 x 10). Excluded patients will be replaced.
研究类型
阶段
- 不适用
联系人和位置
学习地点
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Copenhagen Ø、丹麦、2100
- Rigshospitalet, Anæstesi og Operationsklinikken 2043
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参与标准
资格标准
适合学习的年龄
接受健康志愿者
有资格学习的性别
描述
Inclusion Criteria:
- Patients undergoing one of the following vascular surgical interventions in general anesthesia: Infra-inguinal bypass, femoro-femoral cross-over bypass or iliofemoral bypass surgery.
- Age > 18 years. Informed consent
Exclusion Criteria:
- Use of monoamine oxidase inhibitors
- Allergy to phenylephrine
- Patients that cannot cooperate during examination
- Dementia defined as Mini-Mental State Examination < 24
- Anesthesia within the last 30 days
- Alcohol consumption at or above 420 grams per week
- Lack of fluency in written and spoken Danish
- Severe hearing and vision impairment
- Neurological disease
学习计划
研究是如何设计的？
设计细节
- 主要用途：支持治疗
- 分配：随机化
- 介入模型：并行分配
- 屏蔽：三倍
武器和干预
参与者组/臂 |
干预/治疗 |
|---|---|
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实验性的：MAP maintained at 80 mmHg
During anesthesia MAP is maintained at 80 - 90 mmHg MAP using continuous infusion of phenylephrine.
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Intervention group, MAP is maintained at 80 - 90 mmHg during anesthesia using continuous infusion of phenylephrine.
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有源比较器：MAP maintained at 60 mmHg
During anesthesia MAP is maintained at minimum of 60 mmHg using continuous infusion of phenylephrine.
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Control group, MAP is maintained at minimum of 60 mmHg during anesthesia using continuous infusion of phenylephrine.
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研究衡量的是什么？
主要结果指标
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
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Middle cerebral artery blood velocity
大体时间：During surgery
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Middle cerebral artery blood velocity measured in [cm/s] assessed by transcranial Doppler.
Changes in middle cerebral artery blood velocity reflects changes in cerebral blood flow.
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During surgery
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次要结果测量
结果测量 |
措施说明 |
大体时间 |
|---|---|---|
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Change in serum S100B as compared between subjects in the control- and intervention groups
大体时间：Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
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Serum concentrations of S100B, a marker of neuronal injury
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Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
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Change in serum neuron-specific enolase as compared between subjects in the control- and intervention groups
大体时间：Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
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Serum concentrations of neuron-specific enolase, a marker of neuronal injury
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Blood is sampled 10 min prior to induction of anesthesia and at the end of surgery
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Regional cerebral oxygenation as compared between subjects in the control- and intervention groups
大体时间：During surgery
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Frontal lobe oxygenation measured as the percentage of oxyhemoglobin of total hemoglobin [%] evaluated by near-infrared spectroscopy
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During surgery
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Cardiac output as compared between subjects in the control- and intervention groups
大体时间：During surgery
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Cardiac output measured in [l/min] evaluated by pulse contour analysis of the arterial blood pressure curve
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During surgery
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Stroke volume as compared between subjects in the control- and intervention groups
大体时间：During surgery
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Stroke volume measured in [ml/min] evaluated by pulse contour analysis of the arterial blood pressure curve
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During surgery
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合作者和调查者
调查人员
- 首席研究员：Niels D. Olesen, MD、Rigshospitalet, Anæstesi og Operationsklinikken 2043, Denmark
研究记录日期
研究主要日期
学习开始 (预期的)
初级完成 (预期的)
研究完成 (预期的)
研究注册日期
首次提交
首先提交符合 QC 标准的
首次发布 (估计)
研究记录更新
最后更新发布 (实际的)
上次提交的符合 QC 标准的更新
最后验证
更多信息
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MAP maintained at 80 mmHg的临床试验
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