Johnson M A, Woodcock A A, Rehahn M, Geddes D M
Br Med J (Clin Res Ed). 1983 Jan 15;286(6360):179-82. doi: 10.1136/bmj.286.6360.179.
Breathlessness, disability, and exercise tolerance were assessed in 26 patients with severe chronic airflow limitation (forced expiratory volume in one second (FEV1) less than or equal to 1 litre) divided into two groups--15 patients who were normocapnic (pressure of arterial carbon dioxide (Paco2) less than 5.5 kPa (less than 41.4 mm Hg)), and 11 patients who were hypercapnic (Paco2 greater than 6 kPa (greater than than 45.1 mm Hg)). The two groups were well matched for spirometric values (FEV1 0.59 1 and 0.62 1, respectively). All of the hypercapnic patients could improve blood gas tensions towards normal by hyperventilation. There were no significant differences in visual analogue scores of breathlessness during treadmill exercise, disability (oxygen-cost diagram, dyspnoea grade), or exercise tolerance (six-minute walk, maximal consumption of oxygen during bicycle ergometry, distance walked to exhaustion in progressive treadmill test). The findings show that the "fight" to maintain normal blood gas tensions in the face of severe airflow limitation does not have an appreciable cost in terms of disability.
对26例严重慢性气流受限（一秒用力呼气容积（FEV1）小于或等于1升）患者的呼吸困难、功能障碍和运动耐力进行了评估，这些患者被分为两组——15例血二氧化碳正常（动脉血二氧化碳分压（Paco2）小于5.5kPa（小于41.4mmHg））的患者和11例高碳酸血症（Paco2大于6kPa（大于45.1mmHg））的患者。两组的肺量计值（FEV1分别为0.59升和0.62升）匹配良好。所有高碳酸血症患者均可通过过度通气使血气张力恢复正常。在跑步机运动期间的呼吸困难视觉模拟评分、功能障碍（氧耗图、呼吸困难分级）或运动耐力（6分钟步行、自行车测力计期间的最大耗氧量、递增跑步机试验中直至疲惫的步行距离）方面，两组之间均无显著差异。研究结果表明，面对严重气流受限时为维持正常血气张力而进行的“斗争”，在功能障碍方面并无明显代价。
