Pulmonary blood flow heterogeneity during hypoxia and high-altitude pulmonary edema
Pulmonary blood flow heterogeneity during hypoxia and high-altitude pulmonary edema
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DOI：
10.1164/rccm.200406-707oc
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发表时间：
2005-01-01
影响因子：
24.7
通讯作者：
Levin, DL
中科院分区：
文献类型：
--
作者：
Hopkins, SR;Garg, J;Levin, DL
在高原肺水肿(HAPE)中，不均匀的缺氧性肺血管收缩被认为是将部分肺毛细血管床暴露在高压和血管损伤之下。我们假设，有HAPE病史的受试者会在低氧期间表现出肺血流的异质性增加。使用功能磁共振成像技术(动脉自旋标记)对三组受试者的肺血流空间异质性进行了量化：(1)HAPE易感(n=5)，有医生记录的HAPE病史；(2)HAPE抵抗(n=6)，反复暴露于高原而没有疾病；(3)未选择(n=6)，最少有高原暴露史的人。数据收集在常压和常压低氧5、10、20、30分钟后(F-LO2=0.125)。以信号强度的相对离散度(SD/Mean)作为灌注不均的指标。低氧时各组间血氧饱和度无明显差异。常氧条件下，肺组织相对弥散度差异无统计学意义(HAPE敏感组0.940.05，HAPE抵抗组0.94OOS，非HAPE组0.87±0.06；扫描电子显微镜均值)，但HAPE易感组(30min后为1.10±0.0001)增加，HAPE抵抗组(0.91±0.05)和未选择组(0.87±0.0OS)无明显差异。HAPE易感个体在急性缺氧时肺血流的异质性增加，与不均匀的缺氧性肺血管收缩一致。
Uneven hypoxic pulmonary vasoconstriction has been proposed to expose parts of the pulmonary capillary bed to high pressure and vascular injury in high-altitude pulmonary edema (HAPE). We hypothesized that subjects with a history of HAPE would demonstrate increased heterogeneity of pulmonary blood flow during hypoxia. A functional magnetic resonance imaging technique (arterial spin labeling) was used to quantify spatial pulmonary blood flow heterogeneity in three subject groups: (1) HAPE-susceptible (n = 5), individuals with a history of physician-documented HAPE; (2) HAPE-resistant (n = 6), individuals with repeated high-altitude exposure without illness; and (3) unselected (n = 6), individuals with a minimal history of altitude exposure. Data were collected in normoxia and after 5, 10, 20, and 30 minutes of normobaric hypoxia (F-lo2 = 0.125). Relative dispersion (SD/mean) of the signal intensity was used as an index of perfusion heterogeneity. Oxygen saturation was not different between groups during hypoxia. Relative dispersion was not different between groups (HAPE-susceptible 0.94 0.05, HAPE-resistant 0.94 O.OS, unselected 0.87 + 0.06; means SEM) during normoxia, but it was increased by hypoxia in HAPE-susceptible (to 1.10 + 0.05 after 30 minutes, p < 0.0001) but not in HAPE-resistant (0.91 + 0.05) or unselected subjects (0.87 + O.OS). HAPE-susceptible individuals have increased pulmonary blood flow heterogeneity in acute hypoxia, consistent with uneven hypoxic pulmonary vasoconstriction.