Lung mechanics and airway reactivity in sheep during development of oxygen toxicity.
Lung mechanics and airway reactivity in sheep during development of oxygen toxicity.
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羊在氧中毒过程中的肺力学和气道反应性。
DOI：
10.1152/jappl.1990.69.5.1779
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Newman,JH
中科院分区：
文献类型：
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作者：
Fukushima,M;King,LS;Kang,KH;Banerjee,M;Newman,JH
氧气中毒导致呼吸窘迫的原因尚不清楚。本研究的目的是更好地定义呼吸 100% O2 引起的气道异常。通过仪器测量绵羊的动态顺应性（Cdyn）、身体体积描记法（FRC）的功能残气量、血流动力学和肺淋巴流量。每天在施加 15 cmH2O 45 分钟连续气道正压通气 (CPAP) 之前、期间和之后测量 Cdyn 和 FRC。每天测量将 Cdyn 从基线 (ED35) 降低 35% 所需的气雾剂组胺量以及对气雾剂异丙肾上腺素的反应。 Cdyn 从基线时的 0.083 +/- 0.005 (SE) 1/cmH2O 逐渐下降至 96 小时 O2 时的 0.032 +/- 0.004 l/cm H2O。令人惊讶的是，FRC 没有下降（基线时为 1,397 +/- 153 ml，96 小时时为 1,523 +/- 139 ml）。组胺的 ED35 不会因天数或空气对照而发生变化。异丙肾上腺素使 Cdyn 产生变量不一致的增加。我们还测量了其他五只羊呼吸频率和静压-容积关系变化期间 Cdyn 的变化。我们发现氧气毒性对顺应性和肺硬度的增加具有较小但显着的频率依赖性。我们得出的结论是，在成年绵羊中，O2 毒性会降低 Cdyn，但不会增加气道反应性。 O2 毒性中 Cdyn 的大幅降低是由于气道反应性增加或肺容量减少以外的过程造成的，并且 Cdyn 在肺水肿发生之前降低。
The causes of respiratory distress in O2 toxicity are not well understood. The purpose of this study was to better define the airway abnormalities caused by breathing 100% O2. Sheep were instrumented for measurements of dynamic compliance (Cdyn), functional residual capacity by body plethysmography (FRC), hemodynamics, and lung lymph flow. Each day Cdyn and FRC were measured before, during, and after the application of 45 min continuous positive airway pressure (CPAP) at 15 cmH2O. The amount of aerosol histamine necessary to reduce Cdyn 35% from baseline (ED35) was measured each day as was the response to aerosol metaproterenol. Cdyn decreased progressively from 0.083 +/- 0.005 (SE) 1/cmH2O at baseline to 0.032 +/- 0.004 l/cm H2O at 96 h of O2. Surprisingly, FRC did not decrease (1,397 +/- 153 ml at baseline vs. 1,523 +/- 139 ml at 96 h). The ED35 to histamine did not vary among days or from air controls. Metaproterenol produced a variable inconsistent increase in Cdyn. We also measured changes in Cdyn during changes in respiratory rate and static pressure-volume relationships in five other sheep. We found a small but significant frequency dependence of compliance and an increase in lung stiffness with O2 toxicity. We conclude that in adult sheep O2 toxicity reduces Cdyn but does not increase airway reactivity. The large reduction in Cdyn in O2 toxicity results from processes other than increased airway reactivity or reduced lung volume, and Cdyn decreases before the development of lung edema.