Mitrouska I, Tsoumakidou M, Prinianakis G, Milic-Emili J, Siafakas N M
Department of Thoracic Medicine, University Hospital of Heraklion, 711 10 Heraklion, Crete, Greece.
Respir Physiol Neurobiol. 2007 Aug 1;157(2-3):290-4. doi: 10.1016/j.resp.2007.01.014. Epub 2007 Jan 30.
Near the end of a maximal voluntary breath-hold, re-inhalation of the expired gas allows an additional period of breath-holding, indicating that the breaking point does not depend solely on chemical drive. We hypothesized that afferents from respiratory muscle and/or chest wall are significant in breath-holding.
Nineteen normal adults breathed room air through a mouthpiece connected to a pneumotachograph and were instructed to breath-hold with and without voluntary regular respiratory efforts against an occluded airway.
Fifty one trials with and 53 without respiratory efforts were analyzed. The mean number of efforts per minute was 19+/-2.3 and the mean lowest airway pressure (P(aw)) -16.6+/-5.4 cmH(2)O. Breath-holding time (BHT) did not differ without (33.0+/-18.2 s) and with (29.3+/-12.3 s) efforts. In five patients arterial blood gasses were measured before and at the end of breath-holding and they did not differ between trials without and with efforts, indicating similar chemical drive. Our results suggest that afferents from respiratory muscle and/or chest wall are not the major determinants of BHT.
在最大自主屏气接近尾声时，重新吸入呼出气体可使屏气时间延长，这表明屏气的终止点并非仅取决于化学驱动。我们推测来自呼吸肌和/或胸壁的传入神经在屏气过程中起重要作用。
19名正常成年人通过连接在呼吸流速仪上的咬嘴呼吸室内空气，并被要求在气道阻塞的情况下进行屏气，屏气时分别有无自主规律的呼吸动作。
分析了51次有呼吸动作和53次无呼吸动作的试验。每分钟的平均动作次数为19±2.3次，平均最低气道压力（P(aw)）为-16.6±5.4 cmH₂O。屏气时间（BHT）在无呼吸动作时（33.0±18.2秒）和有呼吸动作时（29.3±12.3秒）并无差异。对5名患者在屏气前和屏气结束时进行了动脉血气测量，结果显示有、无呼吸动作的试验之间并无差异，表明化学驱动相似。我们的结果表明，来自呼吸肌和/或胸壁的传入神经并非屏气时间的主要决定因素。
