Effects of Hypobaric Hypoxia on Cerebral Autoregulation
Effects of Hypobaric Hypoxia on Cerebral Autoregulation
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DOI：
10.1161/strokeaha.109.574749
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发表时间：
2010-04-01
期刊：
影响因子：
8.3
通讯作者：
Roach, Robert C.
中科院分区：
文献类型：
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作者：
Subudhi, Andrew W.;Panerai, Ronney B.;Roach, Robert C.
背景和目的-急性缺氧与脑自动调节（CA）受损有关，但长期缺氧时CA的改变是否是脑病理学发展的关键，如急性高原反应（AMS）中所见，目前尚不清楚。本研究评价了低压缺氧9小时以上CA和AMS之间的关系。方法对55名受试者（41名男性，14名女性）在常氧（P（B）=625 mm Hg）和低压缺氧4小时和9小时后（P（B）=425 mm Hg;近似4875 m）进行了研究。在呼吸室内空气的同时，记录每个时间点的静息、逐搏动脉血压和大脑中动脉血流速度的变化。传递函数分析用于估计自动调节指数（ARI）。在29名受试者中，还测定了等二氧化碳高氧时的ARI和改良再呼吸时的脑血管反应性，以分离缺氧和CO（2）反应性对CA的影响。结果：自我报告的露易丝湖AMS问卷评分≥ 3分的头痛患者用于区分AMS阳性（n=27）和AMS阴性（n=28）受试者（P
Background and Purpose-Acute hypoxia is associated with impairment of cerebral autoregulation (CA), but it is unclear if altered CA during prolonged hypoxia is pivotal to the development of cerebral pathology, such as that seen in acute mountain sickness (AMS). This investigation evaluated relationship between CA and AMS over 9 hours of hypobaric hypoxia.Methods-Fifty-five subjects (41 males, 14 females) were studied in normoxia (P(B)=625 mm Hg) and after 4 and 9 hours of hypobaric hypoxia (P(B)=425 mm Hg; approximate to 4875 m). Resting, beat-by-beat changes in arterial blood pressure, and middle cerebral artery blood flow velocity were recorded at each time point while breathing room air. Transfer function analyses were used to estimate autoregulation indices (ARI). In 29 subjects, ARI during isocapnic hyperoxia and cerebral vasomotor reactivity during modified rebreathing were also determined to isolate effects of hypoxia and CO(2) reactivity on CA.Results-Self-reported Lake Louise AMS Questionnaire scores >= 3 with headache were used to differentiate between AMS-positive (n=27) and AMS-negative (n=28) subjects (P