Bai T R, Rabinovitch B J, Pardy R L
J Appl Physiol Respir Environ Exerc Physiol. 1984 Dec;57(6):1742-8. doi: 10.1152/jappl.1984.57.6.1742.
Because of its potential relevance to heavy exercise we studied the ventilatory muscle function of five normal subjects before, during, and after shortterm near-maximal voluntary normocapnic hyperpnea. Measurements of pleural and abdominal pressures and diaphragm electromyogram (EMG) during hyperpnea and of maximum respiratory pressures before and after hyperpnea were made at four levels of ventilation: 76, 79, and 86% maximal voluntary ventilation (MVV) and at MVV. Measurements of pleural and abdominal pressures and diaphragm electromyogram (EMG) during hyperpnea and of maximum respiratory pressures before and after hyperpnea were made. The pressure-stimulation frequency relationship of the diaphragm obtained by unilateral transcutaneous phrenic nerve stimulation was studied in two subjects before and after hyperpnea. Decreases in maximal inspiratory (PImax) and transdiaphragmatic (Pdimax) strength were recorded posthyperpnea at 76 and 79% MVV. Decreases in the pressure-frequency curves of the diaphragm and the ratio of high-to-low frequency power of the diaphragm EMG occurred in association with decreases in Pdimax. Analysis of the pressure-time product (P X dt) for the inspiratory and expiratory muscles individually indicated the increasing contribution of expiratory muscle force to the attainment of higher levels of ventilation. Demonstrable ventilatory muscle fatigue may limit endurance at high levels of ventilation.
由于其与剧烈运动的潜在相关性，我们研究了5名正常受试者在短期接近最大自主正常碳酸血症性通气过度之前、期间和之后的通气肌功能。在四个通气水平下进行了测量：最大自主通气量（MVV）的76%、79%、86%以及MVV时，测量了通气过度期间的胸膜和腹部压力以及膈肌肌电图（EMG），以及通气过度前后的最大呼吸压力。测量了通气过度期间的胸膜和腹部压力以及膈肌肌电图（EMG），以及通气过度前后的最大呼吸压力。在两名受试者通气过度前后研究了通过单侧经皮膈神经刺激获得的膈肌压力-刺激频率关系。通气过度后，在MVV的76%和79%时记录到最大吸气力量（PImax）和跨膈力量（Pdimax）下降。膈肌压力-频率曲线以及膈肌EMG高低频功率比值的下降与Pdimax的下降相关。分别对吸气肌和呼气肌的压力-时间乘积（P×dt）进行分析表明，呼气肌力量对达到更高通气水平的贡献增加。明显的通气肌疲劳可能会限制高水平通气时的耐力。
