Newman S P, Woodman G, Morén F, Clarke S W
Department of Thoracic Medicine, Royal Free Hospital, London.
Br J Dis Chest. 1988 Jul;82(3):262-7. doi: 10.1016/0007-0971(88)90066-6.
Metered dose inhalers are sometimes used in conjunction with NebuhalerR, a 750 ml holding chamber, but the permissible delay time between actuating the aerosol into Nebuhaler and commencing inhalation is unknown. We have compared in 10 asthmatic patients the bronchodilator responses following inhalations of terbutaline sulphate from Nebuhaler after delays of 1, 5 and 30 seconds and following placebo inhalation. Terbutaline sulphate was administered as 2 puffs, each of 250 micrograms, separated by approximately 15 minutes. After each delay time, terbutaline produced increases in forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR) and maximum expiratory flow following exhalation of 75% of the forced vital capacity (V max25) significantly greater than those after placebo (P less than 0.01). Changes in PEFR did not vary significantly among the three delay times, but the increases in FEV1 and in V max25 were significantly reduced with 30 seconds' delay. It is concluded that the delay between actuation into Nebuhaler and commencing inhalation can be extended from 1 second to 5 seconds without significant loss of drug efficacy, and that further extension to 30 seconds causes only a small loss of bronchodilatation: hence the delay time is unlikely to be of major importance in clinical practice.
定量吸入器有时会与容积为750毫升的储雾罐NebuhalerR联合使用，但将气雾剂喷入Nebuhaler后开始吸入的允许延迟时间尚不清楚。我们比较了10名哮喘患者在延迟1秒、5秒和30秒后从Nebuhaler吸入硫酸特布他林后的支气管扩张反应以及吸入安慰剂后的反应。硫酸特布他林以2吸给药，每次250微克，间隔约15分钟。在每个延迟时间后，特布他林使一秒用力呼气量（FEV1）、呼气峰值流速（PEFR）以及呼出75%用力肺活量后的最大呼气流量（V max25）的增加显著大于安慰剂后的增加（P<0.01）。三个延迟时间之间PEFR的变化没有显著差异，但延迟30秒时FEV1和V max25的增加显著减少。结论是，喷入Nebuhaler后开始吸入之间的延迟可以从1秒延长至5秒而不会显著损失药物疗效，进一步延长至30秒只会导致支气管扩张作用有少量损失：因此，延迟时间在临床实践中不太可能具有重要意义。
