O'Donnell D E, Chau L K, Webb K A
Division of Respiratory and Critical Care Medicine, Department of Medicine, Queen's University, Kingston, Ontario, Canada K7L 2V7.
J Appl Physiol (1985). 1998 Jun;84(6):2000-9. doi: 10.1152/jappl.1998.84.6.2000.
We compared qualitative and quantitative aspects of perceived exertional dyspnea in patients with interstitial lung disease (ILD) and normal subjects and sought a physiological rationale for their differences. Twelve patients with ILD [forced vital capacity = 64 +/- 4 (SE) %predicted] and 12 age-matched normal subjects performed symptom-limited incremental cycle exercise tests with measurements of dyspnea intensity (Borg scale), ventilation, breathing pattern, operational lung volumes, and esophageal pressures (Pes). Qualitative descriptors of dyspnea were selected at exercise cessation. Both groups described increased "work and/or effort" and "heaviness" of breathing; only patients with ILD described "unsatisfied inspiratory effort" (75%), "increased inspiratory difficulty" (67%), and "rapid breathing" (58%) (P < 0.05 patients with ILD vs. normal subjects). Borg-O2 uptake (VO2) and Borg-ventilation slopes were significantly greater during exercise in patients with ILD (P < 0.01). At peak exercise, when dyspnea intensity and inspiratory effort (Pes-to-maximal inspiratory pressure ratio) were similar, the distinct qualitative perceptions of dyspnea in patients with ILD were attributed to differences in dynamic ventilatory mechancis, i.e., reduced inspiratory capacity, heightened Pes-to-tidal volume ratio, and tachypnea. Factors contributing to dyspnea intensity in both groups were also different: the best correlate of the Borg-VO2 slope in patients with ILD was the resting tidal volume-to-inspiratory capacity ratio (r = 0.58, P < 0.05) and in normal subjects was the slope of Pes-to-maximal inspiratory pressure ratio over VO2 (r = 0.60, P < 0. 05).
我们比较了间质性肺疾病（ILD）患者和正常受试者在感知运动性呼吸困难方面的定性和定量特征，并探寻了两者差异的生理学依据。12例ILD患者[用力肺活量=64±4（SE）%预计值]和12名年龄匹配的正常受试者进行了症状限制递增式蹬车运动试验，同时测量呼吸困难强度（Borg量表）、通气、呼吸模式、有效肺容积和食管压力（Pes）。在运动结束时选择呼吸困难的定性描述词。两组均描述了呼吸时“工作和/或努力”增加以及“沉重感”；只有ILD患者描述了“吸气努力未满足”（75%）、“吸气困难增加”（67%）和“呼吸急促”（58%）（ILD患者与正常受试者相比，P<0.05）。ILD患者运动期间的Borg-摄氧量（VO2）和Borg-通气斜率显著更大（P<0.01）。在运动峰值时，当呼吸困难强度和吸气努力（Pes与最大吸气压力比值）相似时，ILD患者对呼吸困难的不同定性感受归因于动态通气机制的差异，即吸气能力降低、Pes与潮气量比值升高以及呼吸急促。两组中导致呼吸困难强度的因素也不同：ILD患者中Borg-VO2斜率的最佳相关因素是静息潮气量与吸气能力比值（r=0.58，P<0.05），而在正常受试者中是Pes与最大吸气压力比值相对于VO2的斜率（r=0.60，P<0.05）。
