Riley D J, Weitz B W, Edelman N H
Am Rev Respir Dis. 1976 Sep;114(3):509-15. doi: 10.1164/arrd.1976.114.3.509.
Asthmatics are usually instructed to use pressurized bronchodilator aerosols by delivering a bolus of drug at the beginning of a full inspiration. Because airways are better dilated near total lung capacity, the delivery of the drug near the end of a full breath might allow better penetration of particles into the lung and greater bronchodilatation. To test this hypothesis, 13 asthmatic subjects inhaled 400 mug of isoproterenol at 20 per cent (low) and at 80 per cent (high) vital capacity. The studies were done on 2 separate days when the severity of asthma was the same. Forced vital capacity, 1-sec forced expiratory volume, specific airway conductance and maximal flow at 50 per cent of viral capacity were measured at frequent intervals after drug administration. Ten min after drug delivery, there was a significantly greater (P less than 0.05) improvement in 1-sec forced expiratory volume after the drug was inhaled at the high lung volume compared to the response after delivery at the low lung volume. The differences in forced vital capacity, specific conductance, and maximal flow at 50 per cent of vital capacity were not significant. We concluded that inhaling a bronchodilator drug at the end of a full inspiration causes relatively greater bronchodilatation than inhaling the same dose at the beginning of inspiration.
通常指导哮喘患者在深吸气开始时使用加压支气管扩张气雾剂来输送大剂量药物。由于在接近肺总量时气道扩张得更好，在深吸气接近结束时输送药物可能会使药物颗粒更好地渗透到肺内，并产生更大程度的支气管扩张。为了验证这一假设，13名哮喘患者在肺活量的20%（低）和80%（高）时吸入400微克异丙肾上腺素。这些研究在哮喘严重程度相同的2个不同日子进行。给药后频繁测量用力肺活量、1秒用力呼气量、比气道传导率和肺活量50%时的最大流速。给药10分钟后，与在低肺容积时给药后的反应相比，在高肺容积时吸入药物后1秒用力呼气量有显著更大（P小于0.05）的改善。用力肺活量、比传导率和肺活量50%时的最大流速差异不显著。我们得出结论，在深吸气结束时吸入支气管扩张药物比在吸气开始时吸入相同剂量药物会导致相对更大程度的支气管扩张。
