Hill A R, Kaiser D L, Lu J Y, Rochester D F
Respir Physiol. 1985 Sep;61(3):369-81. doi: 10.1016/0034-5687(85)90079-9.
To determine the predominant steady-state ventilatory responses to mild expiratory flow-resistive loads, we subjected 14 normal subjects to expiratory resistances of 0-10 cm H2O/L/sec (R0-R3). Breathing patterns and abdominal muscle activity (EMG) were recorded during quiet breathing, and when ventilation was augmented by dead space breathing (7 subjects) or treadmill walking (7 subjects). Expiratory loading increased expiratory time (TE), tidal volume and mean inspiratory flow rate, while decreasing inspiratory duty cycle and respiratory frequency. Minute ventilation (VI) remained constant. These load responses were most prominent during quiet breathing, and were attenuated or abolished as VI increased. Abdominal EMG was negligible during quiet breathing, increased when VI increased, but showed no consistent response to R1-R3. Thus, the principal defense against mild expiratory loads is prolongation of expiration, accompanied by enhanced inspiratory drive. Abdominal muscle expiratory activity is elicited by increasing ventilation, but occurs only sporadically with expiratory loading of the magnitude studied.
为了确定对轻度呼气气流阻力负荷的主要稳态通气反应，我们让14名正常受试者承受0至10厘米水柱/升/秒（R0 - R3）的呼气阻力。在安静呼吸期间，以及当通过死腔呼吸（7名受试者）或跑步机行走（7名受试者）增加通气量时，记录呼吸模式和腹部肌肉活动（肌电图）。呼气负荷增加了呼气时间（TE）、潮气量和平均吸气流速，同时降低了吸气占空比和呼吸频率。分钟通气量（VI）保持恒定。这些负荷反应在安静呼吸时最为明显，并随着VI的增加而减弱或消失。安静呼吸时腹部肌电图可忽略不计，当VI增加时增加，但对R1 - R3没有一致的反应。因此，对轻度呼气负荷的主要防御是呼气延长，同时伴有吸气驱动力增强。腹部肌肉呼气活动是由通气增加引起的，但仅在研究的负荷量的呼气负荷时偶尔出现。
