Romo-Salas F, Aquin L, Searles J M, Banchero N
Respiration. 1978;35(4):186-91. doi: 10.1159/000193877.
The O2 cost of breathing has been calculated in awake and anesthetized dogs breathing spontaneously. Respiratory variables were measured in tracheostomized dogs in the standing position, while supported in a canvas sling, at room temperatures between 20 and 23 degrees C. Minute ventilation ranged between 3 and 53 liters/min while VO2 ranged from 61 to 686 ml/min. VE, VO2 and f varied considerably from measurement to measurement even though body temperatures and experimental conditions changed very little. VO2 increased with VE: VO2 = 10.2 VE + 58.4 r = 0.94. A cubic polynomial equation was also calculated for these data: VO2 = 11.6 + 19.0 VE-0.42 (VE)2 + 0.0057 (VE)3. Awake dogs showed panting and considerable hyperventilation (PACO2 = 22.5 +/- SD of 4.5 mm Hg). Anesthetized dogs had lower average values of f, VE and VO2; while average PACO2 was 29.1 +/- 4.5 mm Hg. VO2 and VE measured when the dogs were anesthetized, paralyzed and artifically ventilated were related by this equation: VO2 = 5.9 VE + 87.5, r = 0.88. The O2 cost of breathing, calculated by subtracting the regression equation obtained while the dogs were under artificial respiration, from the cubic polynomial equation, increased with increasing VE in a curvilinear fashion. The values for O2 cost of breathing at high levels of ventilation were high because dogs' lungs are small. After correcting for lung size, values for O2 cost of breathing were similar to those in humans.
已计算出自发性呼吸的清醒和麻醉犬的呼吸耗氧量。在20至23摄氏度的室温下，对站立于帆布吊床中并经气管切开的犬测量呼吸变量。分钟通气量在3至53升/分钟之间，而耗氧量在61至686毫升/分钟之间。尽管体温和实验条件变化很小，但每次测量时的每分钟通气量（VE）、耗氧量（VO₂）和呼吸频率（f）仍有很大差异。VO₂随VE增加：VO₂ = 10.2VE + 58.4，r = 0.94。还针对这些数据计算了一个三次多项式方程：VO₂ = 11.6 + 19.0VE - 0.42(VE)² + 0.0057(VE)³。清醒犬表现出喘气和明显的过度通气（动脉血二氧化碳分压（PACO₂） = 22.5 ± 标准差4.5毫米汞柱）。麻醉犬的f、VE和VO₂的平均值较低；而平均PACO₂为29.1 ± 4.5毫米汞柱。犬在麻醉、麻痹并人工通气时测得的VO₂和VE符合此方程：VO₂ = 5.9VE + 87.5，r = 0.88。通过从三次多项式方程中减去犬在人工呼吸时获得的回归方程来计算呼吸的耗氧量，其随VE增加呈曲线上升。高通气水平下呼吸耗氧量的值较高，因为犬的肺较小。校正肺大小后，呼吸耗氧量的值与人类相似。
