Fletcher R, Nordström L
Anaesthesia. 1986 Nov;41(11):1135-8. doi: 10.1111/j.1365-2044.1986.tb12965.x.
A 14-year-old boy with a mediastinal tumour large enough to cause dyspnoea at rest was anaesthetised for a biopsy. The tumour was believed to compress the tracheal bifurcation. After tracheal intubation, the expiratory breath sounds were heard to be intermittent. The expiratory flow pattern showed irregularities synchronous with the electrocardiogram. With constant flow inflation, the inspiratory pressure profile was suggestive of mechanical obstruction with a resistance which decreased during inspiration. The airway deadspace was greatly reduced, suggesting that the obstruction was near the tracheal tube opening and that there was pooling of carbon dioxide behind this obstruction. The alveolar deadspace fraction was increased and the shape of the carbon dioxide single breath test suggested severe airway obstruction. These findings can be explained on the basis of large airway obstruction, partly intermittent because of the heart's movement, and also reduced lung volume and uneven gas distribution caused by the tumour and pleural fluid.
一名14岁男孩患有纵隔肿瘤，肿瘤大到足以导致静息时呼吸困难，因需进行活检而接受麻醉。据信该肿瘤压迫气管分叉。气管插管后，呼气呼吸音呈间歇性。呼气流型显示与心电图同步的不规则变化。在恒定流量充气时，吸气压力曲线提示存在机械性梗阻，吸气时阻力降低。气道死腔显著减小，提示梗阻靠近气管导管开口，且该梗阻后方有二氧化碳潴留。肺泡死腔分数增加，二氧化碳单次呼吸试验的图形提示存在严重气道梗阻。这些发现可基于大气道梗阻来解释，部分梗阻因心脏运动而呈间歇性，同时肿瘤和胸腔积液导致肺容积减小和气体分布不均。
