Respiratory Medicine Unit, ASST - Spedali Civili di Brescia, Piazzale Spedali Civili 1, Brescia, Italy.
Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
Lung. 2022 Aug;200(4):473-480. doi: 10.1007/s00408-022-00556-9. Epub 2022 Jul 18.
In patients with chronic obstructive pulmonary disease (COPD), bronchial responsiveness after acute administration of short acting bronchodilators is conventionally assessed by measuring the improvement of forced expiratory volume in the first second (FEV) during a maximal forced expiratory maneuver. This study aimed to measure the variation of intrathoracic airway wall compliance (AWC) after acute administration of short acting beta-2 agonist in COPD patients since this might influence the final modification of airway caliber during maximal expiratory effort and the resulting bronchodilation as inferred by FEV changes.
In a group of 10 patients suffering from COPD, intrathoracic AWC was measured at middle (50% of Forced Vital Capacity (FVC) and low (75% of FVC) lung volumes using the interrupter method during forced expiratory maneuver in basal conditions and after acute inhalation of albuterol (salbutamol) (400 mcg by MDI). Ten healthy subjects were examined similarly as a control group.
Lower values of baseline intrathoracic AWC at both lung volumes were found in COPD patients (1.72 ± 0.20 ml/cmHO and 1.08 ± 0.20 ml/cmHO, respectively) as compared to controls (2.28 ± 0.27 ml/cmHO and 1.44 ± 0.22 ml/cmHO, respectively) (p < 0.001). In COPD patients, AWC increased significantly at both lung volumes after salbutamol, amounting to 1.81 ± 0.38 ml/cmHO and 1.31 ± 0.39 ml/cmHO, respectively (p < 0.01), but the relative change was not different from that observed in controls.
In COPD patients, AWC is reduced compared to controls, but after bronchodilator, the intrathoracic airways become more compliant. The consequent increased collapsibility under high positive pleural pressure could limit the airway caliber improvement seen after bronchodilator, as assessed by the FEV changes during the forced expiratory maneuver, underestimating the effective bronchodilation achieved in these patients.
在慢性阻塞性肺疾病（COPD）患者中，通常通过测量最大用力呼气时第一秒用力呼气量（FEV）的改善来评估急性短效支气管扩张剂给药后支气管的反应性。本研究旨在测量 COPD 患者急性给予短效β2 激动剂后胸内气道壁顺应性（AWC）的变化，因为这可能会影响最大呼气努力期间气道口径的最终变化，以及由此推断的 FEV 变化所带来的支气管扩张。
在一组 10 名患有 COPD 的患者中，在基础状态下和急性吸入沙丁胺醇（沙美特罗）（400μg 通过 MDI）后，使用中断法在用力呼气动作中测量中肺容积（用力肺活量（FVC）的 50%）和低肺容积（FVC 的 75%）时测量胸内 AWC。10 名健康受试者作为对照组进行类似检查。
与对照组（2.28±0.27ml/cmHO 和 1.44±0.22ml/cmHO）相比，COPD 患者在两个肺容积的基础 AWC 值均较低（1.72±0.20ml/cmHO 和 1.08±0.20ml/cmHO）（p<0.001）。在 COPD 患者中，沙丁胺醇后两个肺容积的 AWC 均显著增加，分别为 1.81±0.38ml/cmHO 和 1.31±0.39ml/cmHO（p<0.01），但相对变化与对照组无差异。
与对照组相比，COPD 患者的 AWC 降低，但支气管扩张剂后，胸内气道变得更具顺应性。在高正压胸膜下，增加的气道塌陷可能会限制支气管扩张剂给药后 FEV 用力呼气动作中观察到的气道口径改善，从而低估这些患者的有效支气管扩张。
