Malo J L, L'Archevêque J, Cartier A
Dept of Chest Medicine, Hôpital du Sacré-Coeur, Montreal, Canada.
Eur Respir J. 1990 Jun;3(6):639-43.
The aim of this study was to find out if bronchodilatation following deep inspiration can be induced by the inhalation of a "natural" stimulus (hyperventilation of cold dry air), and if the effect is similar to that induced by methacholine. After baseline assessment of lung resistance (RL), 10 asthmatic subjects were asked to inhale cold dry air for 3 min. RL was monitored continuously for 3-4 min, at which time subjects were asked to take a fast deep inspiration. After recovery, the manoeuvre was repeated and RL was reassessed. The manoeuvre was then repeated a third time. After functional recovery, progressive doses of methacholine were inhaled until the increase in RL was comparable to that obtained after hyperventilation (56 +/- 16% and 65 +/- 24%, respectively, mean +/- SD, NS). The same deep inspiration manoeuvre was repeated three times with recovery as after hyperventilation of cold dry air. Maximum changes in RL were not significantly different after each of the three manoeuvres for either type of bronchoconstriction. The mean fall in RL was 14.2 +/- 9.9% after hyperventilation and 16.4 +/- 10.5% after methacholine. There was a satisfactory correlation (r = 0.80, p less than 0.01) between the bronchodilatation after deep inspiration for both types of stimuli. We conclude that the bronchodilator effect of deep inspiration is no different using either a pharmacological stimulus (methacholine) or a "natural" stimulus (hyperventilation of unconditioned air). These results show that assessing the response to hyperventilation with manoeuvres requiring deep inspiration, forced expiratory volume in one second (FEV1) may alter airway tone in a way similar to pharmacological stimuli.
本研究的目的是探究吸入“自然”刺激物（冷干空气过度通气）是否能诱发深吸气后的支气管扩张，以及该效应是否与乙酰甲胆碱诱发的效应相似。在对肺阻力（RL）进行基线评估后，10名哮喘患者被要求吸入冷干空气3分钟。连续监测RL 3 - 4分钟，此时要求受试者进行一次快速深吸气。恢复后，重复该操作并重新评估RL。然后第三次重复该操作。功能恢复后，吸入递增剂量的乙酰甲胆碱，直至RL的增加与过度通气后相当（分别为56±16%和65±24%，均值±标准差，无显著性差异）。与冷干空气过度通气后一样，在恢复过程中，相同的深吸气操作重复三次。对于两种类型的支气管收缩，在三次操作中的每一次之后，RL的最大变化均无显著差异。过度通气后RL的平均下降为14.2±9.9%，乙酰甲胆碱后为16.4±10.5%。两种刺激物深吸气后的支气管扩张之间存在良好的相关性（r = 0.80，p < 0.01）。我们得出结论，无论是使用药物刺激物（乙酰甲胆碱）还是“自然”刺激物（未调节空气的过度通气），深吸气的支气管扩张效应并无差异。这些结果表明，通过要求深吸气的操作来评估对过度通气的反应时，一秒用力呼气量（FEV1）可能会以类似于药物刺激的方式改变气道张力。
