Akesson U, Dahlström J A, Wollmer P
Department of Clinical Physiology, Malmö University Hospital, Malmö, Sweden.
Clin Physiol. 2000 Jan;20(1):14-8. doi: 10.1046/j.1365-2281.2000.00213.x.
Measurement of the transfer factor for carbon monoxide (TLCO) is a widely used clinical lung function test. Although it is frequently applied in patients with bronchial obstruction, there is little information on the effects of bronchodilatation on the test. We therefore measured TLCO in 40 patients before and after inhalation of terbutaline. TLCO was measured with the single-breath technique in 20 patients and with the intra-breath technique in 20 patients. TLCO was also measured in 20 healthy subjects with the single-breath technique. Forced expiratory volume (FEV1) increased from 2.9 +/- 1. 1 to 3.2 +/- 1.2 l in patients with bronchial obstruction in response to terbutaline inhalation. TLCO increased from 8.2 +/- 2.6 to 8.6 +/- 2.7 mmol min-1 kPa-1 (P< 0.001) and alveolar volume (VA) from 5.74 +/- 1.21 to 5.90 +/- 1.21 l (P<0.001). There was no difference between the single-breath and the intra-breath techniques. There was little change in FEV1 in the healthy subjects in response to terbutaline. TLCO increased from 10.2 +/- 2.1 to 10.5 +/- 2.2 mmol min-1 kPa-1 (P< 0.01), but there was no change in VA. The increase in TLCO in patients may partly be explained by improved distribution of the inhaled gas. In healthy subjects, terbutaline may increase pulmonary capillary volume. We conclude that bronchodilatation results in a small increase in TLCO in patients with light to moderate bronchoconstriction as well as in healthy subjects. The effect is small and should in most cases be simple to account for in the interpretation of pulmonary function tests, provided the patient's treatment is known.
一氧化碳转运因子（TLCO）测定是一种广泛应用的临床肺功能检查。尽管它常用于支气管阻塞患者，但关于支气管扩张对该检查影响的信息却很少。因此，我们对40例患者在吸入特布他林前后进行了TLCO测定。20例患者采用单次呼吸法测量TLCO，另外20例患者采用呼吸中测量法。同时，对20名健康受试者也采用单次呼吸法测量了TLCO。支气管阻塞患者吸入特布他林后，用力呼气量（FEV1）从2.9±1.1升增加到3.2±1.2升。TLCO从8.2±2.6增加到8.6±2.7 mmol·min⁻¹·kPa⁻¹（P<0.001），肺泡容积（VA）从5.74±1.21升增加到5.9升±1.21升（P<0.001）。单次呼吸法和呼吸中测量法之间没有差异。健康受试者吸入特布他林后FEV1变化不大。TLCO从10.2±2.1增加到10.5±2.2 mmol·min⁻¹·kPa⁻¹（P<0.01），但VA没有变化。患者TLCO的增加部分可能是由于吸入气体分布改善所致。在健康受试者中，特布他林可能增加肺毛细血管容积。我们得出结论，支气管扩张导致轻度至中度支气管收缩患者以及健康受试者的TLCO有小幅增加。这种影响较小，并且在大多数情况下，如果已知患者的治疗情况，在解释肺功能检查结果时很容易解释。
