Cosgrove J F, Neunburger N, Bryan M H, Bryan A C, Levison H
Pediatrics. 1975 Dec;56(6):973-80.
Decreased ventilatory response to carbon dioxide is often present in lung disease. This can be due to a reduction in the output of the respiratory center or an inability of the respiratory pump to respond to a normal output because of the size or impedence of the pump. To separate these mechanisms we have measured the isometric force developed by the respiratory muscle during brief airway occlusion, by measuring the pressure generated at 100 msec (Pm100). We studied 43 subjects ranging in age from 6 to 50 years, and nine neonates. We found a linear rise of Pm100 with rising PAco2 during carbon dioxide rebreathing maneuvers. Our results also show that although there are wide variations in slopes of Pm100 to carbon dioxide tension (SPm100/PAco2) between individuals, in a given subject this slope remains constant even following repeated studies. It also remains constant for age and size, indicating that the neuromechanical output of the respiratory apparatus does not change with growth. In contrast the ventilatory response either assessed as Ve/PAco2 or Vt/PAco2 depended on age and lung size. The results suggest that throughout growth, comparison of Pm100/PAco2 and Ve/PAco2 can distinguish between abnormalities of neuromuscular output from other causes of ventilatory impairment.
肺部疾病时常常出现对二氧化碳的通气反应降低。这可能是由于呼吸中枢输出减少，或者是由于呼吸泵的大小或阻力导致呼吸泵无法对正常输出做出反应。为了区分这些机制，我们通过测量在短暂气道阻塞期间呼吸肌产生的等长力，即测量100毫秒时产生的压力（Pm100）。我们研究了43名年龄在6至50岁之间的受试者以及9名新生儿。我们发现，在二氧化碳重复呼吸操作期间，随着动脉血二氧化碳分压（PAco2）升高，Pm100呈线性上升。我们的结果还表明，尽管个体之间Pm100对二氧化碳张力的斜率（SPm100/PAco2）存在很大差异，但在给定的受试者中，即使经过多次研究，该斜率仍保持恒定。它在年龄和体型方面也保持恒定，表明呼吸装置的神经机械输出不会随生长而变化。相比之下，以每分钟通气量（Ve）/PAco2或潮气量（Vt）/PAco2评估的通气反应则取决于年龄和肺大小。结果表明，在整个生长过程中，比较Pm100/PAco2和Ve/PAco2可以区分神经肌肉输出异常与通气障碍的其他原因。
