Goldstein R S, Slutsky A S, Rebuck A S
Drugs. 1978 Sep;16(3):256-67. doi: 10.2165/00003495-197816030-00007.
Asthmatic patients during sympton-free periods almost invariably have abnormalities in lung mechanics and gas exchange. Tentacious secretions and mucosal thickening exaggerate maldistribution of ventilation and cause flow limitation in small airways. Hence, the maximal expiratory flow volume loop in these patients will show impaired flow rates at low lung volumes and many will show a widened alveolar-arterial O2 tension difference. Preventive treatment should be aimed at reversing these abnormalities. The regular use of inhaled sympathomimetics and oral theophylline preparations is justified in the symptom-free patient whose history suggests that he is susceptible to acute exacerbations. Such patients commonly experience an improved sense of well-being, increased exercise tolerance, and a decrease in the frequency and severity of their acute episodes.
无症状期的哮喘患者几乎总是存在肺力学和气体交换异常。黏稠分泌物和黏膜增厚会加剧通气分布不均，并导致小气道出现气流受限。因此，这些患者的最大呼气流量容积环在低肺容量时会显示流速受损，许多患者还会出现肺泡-动脉血氧分压差增大。预防性治疗应旨在纠正这些异常。对于病史表明易发生急性加重的无症状患者，定期使用吸入性拟交感神经药和口服茶碱制剂是合理的。这类患者通常会感觉幸福感增强、运动耐量提高，急性发作的频率和严重程度降低。
