Boulet L P, Turcotte H, Cartier A, Milot J, Côté J, Malo J L, Laviolette M
Le Centre québécois d'excellence en santé respiratoire, Unité de Recherche, Centre de Pneumologie de l'Hôpital Laval, Université Laval, Sainte-Foy, Québec, Canada.
Chest. 1998 Aug;114(2):373-9. doi: 10.1378/chest.114.2.373.
Patient evaluation of asthma severity and medication needs is mostly based on respiratory symptoms and may be influenced by changes in perception of bronchoconstriction-induced sensations. However, the influence of asthma medication on the ability to perceive symptoms is still to be documented. This study evaluated the effects of short-term and regular use of salmeterol on the perception of methacholine-induced bronchoconstriction (MIB) in subjects with mild asthma, using inhaled salbutamol on an "as required" basis (n=15), and in subjects with moderate asthma, using daily inhaled beclomethasone (mean daily dose, 640 microg; n=15) in addition to salbutamol to control their asthma.
Methacholine challenges (MC) were performed at entry into the study, and then before, 1, and 12 h following inhalation of 50 microg of salmeterol or a placebo, after a 15-day baseline period; and after 4 weeks of twice daily use of those treatments. The measurements were then repeated with the alternate treatment after a 15-day washout period. Finally, a last MC was performed after another 15-day washout period. For each MC, the perception score of bronchoconstriction-associated breathlessness at 20% fall in FEV1 (PS20) was evaluated on a modified Borg scale from 0 to 10.
Subjects using regular beclomethasone had a higher baseline PS20 than those using only salbutamol (means: 3.06 0.06 and 2.01+/-0.07, p=0.0001). Short- and long-term use of salmeterol did not change significantly the PS20 compared with placebo (p>0.05) in either group (with or without corticosteroid). Although there were some intraindividual variations, mean PS20 did not vary significantly throughout the study.
These observations show that the perception of bronchoconstriction-associated breathlessness is not influenced by regular use of salmeterol. Patients using inhaled corticosteroids show a greater perception of MIB.
患者对哮喘严重程度和药物需求的评估主要基于呼吸道症状，且可能受支气管收缩引起的感觉变化影响。然而，哮喘药物对症状感知能力的影响仍有待记录。本研究评估了短期和常规使用沙美特罗对轻度哮喘患者（按需使用吸入沙丁胺醇，n = 15）以及中度哮喘患者（除沙丁胺醇外，每日吸入倍氯米松，平均日剂量640微克；n = 15）对乙酰甲胆碱诱发支气管收缩（MIB）的感知的影响。
在15天的基线期后，于研究开始时、吸入50微克沙美特罗或安慰剂之前、之后1小时和12小时进行乙酰甲胆碱激发试验（MC）；在每日两次使用这些治疗4周后重复测量。在15天的洗脱期后，用替代治疗重复测量。最后，在另一个15天的洗脱期后进行最后一次MC。对于每次MC，在FEV1下降20%时，根据改良的Borg量表从0到10评估与支气管收缩相关的呼吸急促的感知评分（PS20）。
常规使用倍氯米松的受试者基线PS20高于仅使用沙丁胺醇的受试者（均值分别为3.06±0.06和2.01±0.07，p = 0.0001）。在两组（使用或未使用皮质类固醇）中，与安慰剂相比，短期和长期使用沙美特罗均未使PS20发生显著变化（p>0.05）。尽管存在个体内差异，但整个研究期间平均PS20无显著变化。
这些观察结果表明，常规使用沙美特罗不影响对支气管收缩相关呼吸急促的感知。使用吸入皮质类固醇的患者对MIB的感知更强。
