Ninane V, Rypens F, Yernault J C, De Troyer A
Chest Service, Erasme University Hospital, Brussels, Belgium.
Am Rev Respir Dis. 1992 Jul;146(1):16-21. doi: 10.1164/ajrccm/146.1.16.
To assess the pattern of abdominal muscle contraction in stable patients with chronic obstructive pulmonary disease (COPD), we studied electromyograms of the rectus abdominis, external oblique, and transversus abdominis muscles in 40 patients with variable degrees of chronic airflow obstruction (FEV1 between 17 and 82% of predicted); 12 control subjects with normal pulmonary function tests were studied for comparison. The subjects were studied during resting breathing in the supine posture, and the electromyograms were recorded with concentric needle electrodes implanted with the aid of a high-resolution ultrasound. The rectus abdominis and external oblique were silent in virtually all patients. In contrast, 17 patients had invariable phasic expiratory activity in the transversus abdominis, and 11 additional patients had intermittent transversus expiratory activity. Expiratory contraction of the transversus was related to the degree of airflow obstruction (p less than 0.005), and when present, it persisted in the seated posture. We conclude that (1) when breathing at rest, many stable patients with severe chronic airflow obstruction contract the abdominal muscles during expiration, and (2) this expiratory contraction is usually confined to the transversus muscle. These observations also indicate that the physiology of dynamic hyperinflation and intrinsic positive end-expiratory pressure (PEEP) in such patients should be reevaluated.
为评估稳定期慢性阻塞性肺疾病（COPD）患者的腹肌收缩模式，我们研究了40例不同程度慢性气流阻塞（FEV1为预计值的17%至82%）患者的腹直肌、腹外斜肌和腹横肌的肌电图；并对12例肺功能测试正常的对照受试者进行了研究以作比较。受试者在仰卧位静息呼吸时接受研究，肌电图通过在高分辨率超声辅助下植入的同心针电极记录。几乎所有患者的腹直肌和腹外斜肌均无活动。相比之下，17例患者的腹横肌有持续的阶段性呼气活动，另有11例患者有间歇性腹横肌呼气活动。腹横肌的呼气收缩与气流阻塞程度相关（p<0.005），且一旦出现，在坐位时仍持续存在。我们得出结论：（1）静息呼吸时，许多重度慢性气流阻塞的稳定期患者在呼气时会收缩腹肌；（2）这种呼气收缩通常局限于腹横肌。这些观察结果还表明，对此类患者动态肺过度充气和内源性呼气末正压（PEEP）的生理机制应重新评估。
