Im Hof V, West P, Younes M
J Appl Physiol (1985). 1986 May;60(5):1471-81. doi: 10.1152/jappl.1986.60.5.1471.
Tidal volume (VT) is usually preserved when conscious humans are made to breathe against an inspiratory resistance. To identify the neural changes responsible for VT compensation we calculated the respiratory driving pressure waveform during steady-state unloaded and loaded breathing (delta R = 8.5 cmH2O X 1(-1) X s) in eight conscious normal subjects. Driving pressure (DP) was calculated according to the method of Younes et al. (J. Appl. Physiol. 51: 963-989, 1981), which provides the equivalent of occlusion pressure at functional residual capacity throughout the breath. VT during resistance breathing was 108% of unloaded VT, as opposed to a predicted value of 82% of control in the absence of neural compensation. Compensation was accomplished through three changes in the DP waveform: 1) peak amplitude increased (+/- 23%), 2) the duration of the rising phase increased (+42%); and 3) the rising phase became more concave to the time axis. There were no changes in the relative decay rate of inspiratory pressure during expiration, in the shape of the declining phase of DP, or in end-expiratory lung volume.
当有意识的人对着吸气阻力呼吸时，潮气量（VT）通常会保持不变。为了确定负责VT补偿的神经变化，我们计算了8名清醒正常受试者在稳态无负荷和有负荷呼吸（δR = 8.5 cmH₂O×1⁻¹×s）期间的呼吸驱动压力波形。驱动压力（DP）根据尤尼斯等人的方法计算（《应用生理学杂志》51: 963 - 989, 1981），该方法在整个呼吸过程中提供相当于功能残气量时的阻断压力。阻力呼吸时的VT是无负荷VT的108%，而在没有神经补偿的情况下预测值为对照值的82%。补偿是通过DP波形的三个变化实现的：1）峰值幅度增加（±23%），2）上升阶段的持续时间增加（+42%）；3）上升阶段相对于时间轴变得更加凹陷。呼气期间吸气压力的相对衰减率、DP下降阶段的形状或呼气末肺容积均无变化。
