摘要
冷风挑战(CACh)可以通过单步(SSCACh)或多步(MSCACh)协议应用。不同协议响应之间的相互关系尚未被研究。此外,在冷空气挑战响应与药理学挑衅结果的相关性上,也有相互矛盾的信息。对28名目前无症状和无药物治疗的支气管哮喘儿童和青少年进行了连续三天的单步、多步冷空气刺激和组胺刺激。单步冷空气激发包括4分钟干燥,-10℃空气等碳强力通气;受试者的反应通过诱导的一秒用力呼气量(FEV1)的变化来量化。多步冷空气激发包括一系列3分钟的冷干空气过度通气步骤,从最大自主通气(MVV)的20 ~ 80%;反应表现为刺激剂量导致FEV1下降10% (PD10)。组胺激发包括一系列吸入2分钟,组胺浓度从0.03逐步增加到8.0 mg.mL-1;反应表现为组胺刺激浓度导致FEV1下降20% (PC20)。 Change in FEV1 (delta FEV1) (SSCACh) correlated closely with PD10 (MSCACh); scatter around the regression line was minimal. With one exception, both types of CACh identified the same subjects as hyper- and normoresponsive. delta FEV1 (SSCACh) correlated significantly to PC20 (histamine), but scatter around the regression line was substantial. The correlation of PD10 (MSCACh) to PC20 (histamine) failed to reach statistical significance. These results indicate that the stimulus applied and the bronchoconstrictor mechanism activated, and not the challenge protocol, determine the outcome of a cold air challenge. In clinical practice, a brief single step cold air challenge can substitute for a more time-consuming multiple step cold air challenge. As nonpharmacological challenges seem to measure a different type of bronchial responsiveness, neither a single step nor a multiple step cold air challenge can substitute for a pharmacological provocation.