Watson Ann, Ind Philip, Pride Neil
Respiratory Medicine, National Heart and Lung Institute, Faculty of Medicine, Imperial College, London, United Kingdom.
J Asthma. 2007 Jul-Aug;44(6):443-8. doi: 10.1080/02770900701421948.
A single deep inspiration (DI) is known to be a potent bronchodilator but it is not known if repeated DI can accelerate sustained recovery from bronchoconstriction.
We induced sustained bronchoconstriction using increasing concentrations of nebulized methacholine (Mch) during tidal breathing and assessed airway narrowing by measuring respiratory resistance (Rrs) using forced oscillation in six healthy subjects. On separate days we examined the effects of DI every 3 minutes and of prohibition of DI on recovery of Rrs for 30 minutes after the end of Mch nebulization.
Bronchoconstriction (Rrs approximately 150% above baseline) was induced. DI during recovery had a transient bronchodilator effect but no cumulative effect. At 30 minutes after end of nebulization (and 2 minutes after the last DI) Rrs was 87% above baseline compared to 93% above baseline when DI was prohibited.
Recovery from induced bronchoconstriction with methacholine was slow (approximately 2%/min) and not accelerated by frequent DI.
单次深吸气(DI)已知是一种有效的支气管扩张剂,但尚不清楚重复深吸气是否能加速支气管收缩后的持续恢复。
在潮式呼吸期间,我们通过增加雾化乙酰甲胆碱(Mch)的浓度诱导持续支气管收缩,并在6名健康受试者中使用强迫振荡测量呼吸阻力(Rrs)来评估气道狭窄。在不同的日子里,我们在乙酰甲胆碱雾化结束后,每隔3分钟检查深吸气的效果以及禁止深吸气对呼吸阻力恢复30分钟的影响。
诱导出支气管收缩(Rrs比基线高约150%)。恢复期间的深吸气有短暂的支气管扩张作用,但无累积效应。雾化结束后30分钟(以及最后一次深吸气后2分钟),呼吸阻力比基线高87%,而禁止深吸气时比基线高93%。
用乙酰甲胆碱诱导的支气管收缩恢复缓慢(约2%/分钟),频繁深吸气并不能加速恢复。