Respiratory Physiology Laboratory, Christchurch Hospital, Christchurch, New Zealand.
Respirology. 2013 Nov;18(8):1223-9. doi: 10.1111/resp.12125.
The bronchodilation and cardiovascular effects of bronchodilators may alter alveolar ventilation and perfusion distribution, which could subsequently affect single-breath diffusing capacity of the lungs for carbon monoxide (DL ,CO) measurements. The aim of this study was to investigate the effect of salbutamol on DL ,CO in subjects with and without airway obstruction and reversibility.
Sixty subjects were investigated with 20 in each of the three groups: normal spirometry; irreversible obstruction; and reversible obstruction. Baseline spirometry, plethysmographic lung volumes, DL ,CO, pulse rate and arterial blood gases were measured. The same testing sequence was repeated after administration of a placebo inhaler and again after 400 μg salbutamol.
Salbutamol did not affect the mean alveolar volume (VA ) (P > 0.05), transfer coefficient for carbon monoxide (DL ,CO/VA , KCO) (P > 0.05) or DL ,CO (P > 0.05) in the normal and irreversible obstruction groups. In the reversible obstruction group, salbutamol caused an increase in the mean VA compared with placebo (P < 0.001). However, the mean KCO was reduced (P < 0.001). The mean change in DL ,CO was not significant (P > 0.05). A considerable reduction in DL ,CO was found after salbutamol in four subjects in the reversible group as a result of a minor increase in VA and substantial decrease in KCO. No statistical difference in pulse rate or arterial blood gases values was detected.
Salbutamol had no effect on the mean DL ,CO in any group. However, salbutamol may considerably reduce DL ,CO in some individuals with reversibility secondary to its effects on VA and KCO.
支气管扩张剂的支气管舒张作用和心血管效应可能会改变肺泡通气和灌注分布，从而影响一氧化碳（CO）的单肺弥散量（DL,CO）测量。本研究旨在探讨沙丁胺醇对存在和不存在气道阻塞及可变性的患者 DL,CO 的影响。
对 60 例患者进行了研究，每组 20 例：正常肺功能；不可逆性阻塞；和可逆转性阻塞。测量基础肺功能、体描法肺容积、DL,CO、脉搏率和动脉血气。给予安慰剂吸入器后和 400μg 沙丁胺醇后重复相同的测试序列。
沙丁胺醇对正常和不可逆性阻塞组的平均肺泡容积（VA）（P > 0.05）、一氧化碳转移系数（DL,CO/VA，KCO）（P > 0.05）或 DL,CO（P > 0.05）均无影响。在可逆转性阻塞组中，与安慰剂相比，沙丁胺醇导致平均 VA 增加（P < 0.001）。然而，平均 KCO 降低（P < 0.001）。DL,CO 的平均变化不显著（P > 0.05）。在可逆转性阻塞组的 4 例患者中，由于 VA 略有增加和 KCO 明显下降，DL,CO 在沙丁胺醇后明显降低。脉搏率或动脉血气值无统计学差异。
沙丁胺醇对任何组的平均 DL,CO 均无影响。然而，沙丁胺醇可能会由于其对 VA 和 KCO 的影响而使一些具有可变性的患者的 DL,CO 明显降低。
