Stick S, Turner D, LeSouëf P
Department of Respiratory Medicine, Princess Margaret Hospital for Children, Perth, West Australia.
J Appl Physiol (1985). 1994 Apr;76(4):1411-6. doi: 10.1152/jappl.1994.76.4.1411.
During the rapid thoracic compression maneuver in infants, the transmission of pressure from compression jacket to pleural space and airway is less at functional residual capacity than at end inspiration. To examine whether reduced pressure transmission at functional residual capacity vs. higher lung volumes is explained by passive characteristics of the chest wall rather than by respiratory muscle activity, we assessed the pressure transmitted across the chest wall in nine anesthetized infants and young children after muscle relaxation. We measured esophageal and airway occlusion pressure during chest compressions at different lung volumes determined by varying distending pressure. In six subjects studied under static conditions, there was an approximately linear relationship between distending pressure and the proportion of pressure transmitted to the airway and esophagus from the compression jacket. The mean r2 value (95% confidence interval) was 0.80 (0.09) for pressure transmission to the airway and 0.85 (0.04) for pressure transmission to the esophagus. This relationship between lung volume and pressure transmission observed under static conditions was also demonstrated dynamically. Thus the reduced transmission of pressure from compression jacket to airway and pleural space at low lung volumes occurs independently of respiratory muscle activity.
在对婴儿进行快速胸廓按压操作时，在功能残气量时，从按压套传递至胸膜腔和气道的压力比在吸气末时要小。为了研究在功能残气量与较高肺容积时压力传递减少是由胸壁的被动特性而非呼吸肌活动所导致的，我们在肌肉松弛后对9名麻醉状态下的婴幼儿进行评估，测量胸壁两侧的压力传递情况。我们在通过改变扩张压力所确定的不同肺容积下进行胸部按压时，测量食管和气道闭塞压力。在6名处于静态条件下研究的受试者中，扩张压力与从按压套传递至气道和食管的压力比例之间存在近似线性关系。压力传递至气道的平均r2值（95%置信区间）为0.80（0.09），传递至食管的为0.85（0.04）。在静态条件下观察到的肺容积与压力传递之间的这种关系在动态情况下也得到了证实。因此，在低肺容积时，从按压套至气道和胸膜腔的压力传递减少独立于呼吸肌活动而发生。
