Nimmo A F, Drummond G B
University Department of Anaesthetics, Royal Infirmary, Edinburgh.
Br J Anaesth. 1996 Sep;77(3):317-26. doi: 10.1093/bja/77.3.317.
We studied 10 patients during the first night after upper abdominal surgery to assess the effect of airway obstruction on chest wall mechanics, by recording nasal gas flow and carbon dioxide concentration, rib cage and abdominal dimensions, abdominal muscle activity, and oesophageal and gastric pressures. The mean duration of study of each subject was 5.8 h, and 5.2 h were analysed. The median proportion of time spent breathing with normal mechanics was 29% (interquartile values 0-57%). Abnormal abdominal mechanical events were common and associated with airway obstruction (P < 0.001). Two common patterns of abnormal pressure and movement were found. In the first, abdominal pressure decreased at the onset of inspiration and there was a phase lag in abdominal movement. The incidence was 33 (14-50)%. In the second pattern, abdominal pressure decreased and in addition the abdominal wall moved inwards at the onset of inspiration. This occurred for 34 (0-52)% of the time. Both patterns were associated with evidence of increased activation of the abdominal muscles during expiration, changing the relationship of abdominal and pleural pressure changes and chest wall movements. Such changes have been interpreted previously as evidence of diaphragm dysfunction.
我们对上腹手术后第一晚的10名患者进行了研究，通过记录鼻气流、二氧化碳浓度、胸廓和腹部尺寸、腹部肌肉活动以及食管和胃内压力，来评估气道阻塞对胸壁力学的影响。每位受试者的平均研究时长为5.8小时，其中5.2小时的记录数据进行了分析。以正常力学模式呼吸的时间中位数比例为29%（四分位间距为0 - 57%）。异常的腹部力学事件很常见，且与气道阻塞相关（P < 0.001）。发现了两种常见的压力和运动异常模式。第一种模式是吸气开始时腹部压力下降，且腹部运动存在相位滞后。其发生率为33（14 - 50）%。第二种模式是腹部压力下降，并且吸气开始时腹壁向内移动。这种情况出现的时间占34（0 - 52）%。两种模式均伴有呼气时腹部肌肉激活增加的证据，这改变了腹部与胸膜压力变化以及胸壁运动之间的关系。此前已将此类变化解释为膈肌功能障碍的证据。
