Gardner W N
J Appl Physiol Respir Environ Exerc Physiol. 1983 Jun;54(6):1726-35. doi: 10.1152/jappl.1983.54.6.1726.
To determine whether change of laryngeal resistance causes shortening of expiratory time (TE) and hence increase of respiratory frequency with CO2 inhalation in conscious humans, 11 fit male subjects with permanent tracheostomies after laryngectomy for cancer (L group) and 8 matched control subjects (C group) inhaled CO2 in mild hyperoxia to produce various levels of steady-state hyperpnea within "nonvagal" range 1. Breathing pattern was averaged at the end of each steady state and behaved similarly in both groups. As end-tidal PCO2 (PACO2) increased, TE significantly shortened in both groups, whereas inspiratory time (TI) remained roughly constant (slightly increasing in the L group), suggesting that the larynx, at least in range 1, has no major role in determining this pattern. Quantitative comparison between the two groups showed that in the L group TE was significantly longer, whereas expiratory flow peaked and declined significantly earlier, resulting in a greater tendency to form end-expiratory pauses. All differences were greatest in eucapnia and decreased as PACO2 increased. Despite matched mean PACO2 values, mean tidal volume (VT) ventilation and mean inspiratory flow (VT/TI) were significantly less in the L group, and the slope of VT/TI vs. PACO2 was significantly depressed.
为了确定在清醒人体中，喉部阻力的变化是否会导致呼气时间（TE）缩短，进而在吸入二氧化碳时导致呼吸频率增加，11名因癌症行喉切除术后有永久性气管造口的健康男性受试者（L组）和8名匹配的对照受试者（C组）在轻度高氧环境中吸入二氧化碳，以在“非迷走神经”范围内产生不同水平的稳态通气过度1。在每个稳态结束时对呼吸模式进行平均，两组表现相似。随着呼气末二氧化碳分压（PACO2）升高，两组的TE均显著缩短，而吸气时间（TI）大致保持恒定（L组略有增加），这表明至少在范围1内，喉部在决定这种模式方面没有主要作用。两组之间的定量比较显示，L组的TE显著更长，而呼气流量峰值出现得更早且下降得更快，导致形成呼气末暂停的趋势更大。所有差异在正常碳酸血症时最大，并随着PACO2升高而减小。尽管两组的平均PACO2值匹配，但L组的平均潮气量（VT）通气和平均吸气流量（VT/TI）显著更低，且VT/TI与PACO2的斜率显著降低。
