Petsonk Edward L, Stansbury Robert C, Beeckman-Wagner Lu-Ann, Long Joshua L, Wang Mei Lin
1 Section of Pulmonary and Critical Care Medicine, Department of Medicine, West Virginia University School of Medicine, Morgantown, West Virginia; and.
2 Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia.
Ann Am Thorac Soc. 2016 Jul;13(7):1076-80. doi: 10.1513/AnnalsATS.201511-786BC.
Coal mine dust exposure can cause symptoms and loss of lung function from multiple mechanisms, but the roles of each disease process are not fully understood.
We investigated the implications of small airway dysfunction for exercise physiology among a group of workers exposed to coal mine dust.
Twenty coal miners performed spirometry, first breathing air and then helium-oxygen, single-breath diffusing capacity, and computerized chest tomography, and then completed cardiopulmonary exercise testing.
Six participants meeting criteria for small airway dysfunction were compared with 14 coal miners who did not. At submaximal workload, miners with small airway dysfunction used a higher proportion of their maximum voluntary ventilation and had higher ventilatory equivalents for both O2 and CO2. Regression modeling indicated that inefficient ventilation was significantly related to small airway dysfunction but not to FEV1 or diffusing capacity. At the end of exercise, miners with small airway dysfunction had 27% lower O2 consumption.
Small airway abnormalities may be associated with important inefficiency of exercise ventilation. In dust-exposed individuals with only mild abnormalities on resting lung function tests or chest radiographs, cardiopulmonary exercise testing may be important in defining causes of exercise intolerance.
接触煤矿粉尘可通过多种机制导致症状和肺功能丧失，但每种疾病过程的作用尚未完全明确。
我们调查了一组接触煤矿粉尘的工人中小气道功能障碍对运动生理学的影响。
20名煤矿工人进行了肺活量测定，先呼吸空气，然后呼吸氦氧混合气，进行单次呼吸弥散功能测定和计算机断层扫描胸部成像，然后完成心肺运动试验。
将6名符合小气道功能障碍标准的参与者与14名不符合该标准的煤矿工人进行比较。在次最大负荷运动时，小气道功能障碍的矿工使用的最大自主通气比例更高，且氧气和二氧化碳的通气当量更高。回归模型表明，通气效率低下与小气道功能障碍显著相关，但与第一秒用力呼气量（FEV1）或弥散功能无关。运动结束时，小气道功能障碍的矿工耗氧量降低了27%。
小气道异常可能与运动通气的重要效率低下有关。在静息肺功能测试或胸部X光片仅有轻度异常的粉尘接触个体中，心肺运动试验对于确定运动不耐受的原因可能很重要。
