Im Hof V, Dubo H, Daniels V, Younes M
J Appl Physiol (1985). 1986 May;60(5):1482-92. doi: 10.1152/jappl.1986.60.5.1482.
Normal subjects preserve tidal volume (VT) in the face of added inspiratory resistance by increasing maximal amplitude and duration of the rising phase of respiratory driving pressure (DP) and by changing the shape of this phase to one that is more concave to the time axis. To explore the possible role of chest wall afferents in mediating these responses, we determined averaged DP in eight quadriplegic subjects during steady-state unloaded breathing and while breathing through an inspiratory resistance (8.5 cmH2O X 1(-1) X s). As with normal subjects, quadriplegics preserved VT (loaded VT = 106% control) by utilizing all three mechanisms. However, prolongation of the inspiratory duration derived from the DP waveform (+22% vs. +42%) and shape response were significantly less in the quadriplegic subjects. Shape response was completely absent in subjects with C4 lesions. The results provide strong evidence that respiratory muscle spindles are responsible for shape response and that changes in afferent feedback from the chest wall play an important role in mediating inspiratory prolongation.
正常受试者在面对额外的吸气阻力时，通过增加呼吸驱动压力（DP）上升阶段的最大幅度和持续时间，并将该阶段的形状改变为更凹向时间轴的形状，来维持潮气量（VT）。为了探究胸壁传入神经在介导这些反应中可能的作用，我们测定了8名四肢瘫痪受试者在稳态无负荷呼吸期间以及通过吸气阻力（8.5 cmH₂O·L⁻¹·s）呼吸时的平均DP。与正常受试者一样，四肢瘫痪者通过利用所有三种机制维持了VT（负荷时VT = 对照值的106%）。然而，四肢瘫痪受试者中，由DP波形得出的吸气持续时间延长（+22% 对 +42%）和形状反应明显较小。C4损伤的受试者完全没有形状反应。结果提供了强有力的证据，表明呼吸肌梭负责形状反应，并且胸壁传入反馈的变化在介导吸气延长中起重要作用。
