Centre for Infection and Immunity, Queen's University Belfast, Belfast City Hospital, Belfast, Northern Ireland; Regional Respiratory Centre, Belfast City Hospital, Belfast, Northern Ireland.
Regional Respiratory Centre, Belfast City Hospital, Belfast, Northern Ireland.
Chest. 2011 May;139(5):1117-1123. doi: 10.1378/chest.10-2321. Epub 2011 Feb 3.
Unexplained persistent breathlessness in patients with difficult asthma despite multiple treatments is a common clinical problem. Cardiopulmonary exercise testing (CPX) may help identify the mechanism causing these symptoms, allowing appropriate management.
This was a retrospective analysis of patients attending a specialist-provided service for difficult asthma who proceeded to CPX as part of our evaluation protocol. Patient demographics, lung function, and use of health care and rescue medication were compared with those in patients with refractory asthma. Medication use 6 months following CPX was compared with treatment during CPX.
Of 302 sequential referrals, 39 patients underwent CPX. A single explanatory feature was identified in 30 patients and two features in nine patients: hyperventilation (n = 14), exercise-induced bronchoconstriction (n = 8), submaximal test (n = 8), normal test (n = 8), ventilatory limitation (n = 7), deconditioning (n = 2), cardiac ischemia (n = 1). Compared with patients with refractory asthma, patients without "pulmonary limitation" on CPX were prescribed similar doses of inhaled corticosteroid (ICS) (median, 1,300 μg [interquartile range (IQR), 800-2,000 μg] vs 1,800 μg [IQR, 1,000-2,000 μg]) and rescue oral steroid courses in the previous year (median, 5 [1-6] vs 5 [1-6]). In this group 6 months post-CPX, ICS doses were reduced (median, 1,300 μg [IQR, 800-2,000 μg] to 800 μg [IQR, 400-1,000 μg]; P < .001) and additional medication treatment was withdrawn (n = 7). Patients with pulmonary limitation had unchanged ICS doses post CPX and additional therapies were introduced.
In difficult asthma, CPX can confirm that persistent exertional breathlessness is due to asthma but can also identify other contributing factors. Patients with nonpulmonary limitation are prescribed inappropriately high doses of steroid therapy, and CPX can identify the primary mechanism of breathlessness, facilitating steroid reduction.
尽管接受了多种治疗，患有难治性哮喘的患者仍持续出现不明原因的呼吸困难，这是一种常见的临床问题。心肺运动测试（CPX）可帮助确定导致这些症状的机制，从而进行适当的管理。
这是对参加我们提供的难治性哮喘专家服务并作为评估方案一部分进行 CPX 的患者进行的回顾性分析。比较了患者的人口统计学特征、肺功能以及保健和抢救药物的使用情况与难治性哮喘患者的使用情况。比较了 CPX 后 6 个月的药物使用情况与 CPX 期间的治疗情况。
在 302 例连续转介中，有 39 例患者接受了 CPX。在 30 例患者中发现了单一的解释性特征，在 9 例患者中发现了两个特征：过度通气（n = 14）、运动诱发的支气管收缩（n = 8）、亚最大测试（n = 8）、正常测试（n = 8）、通气受限（n = 7）、身体适应不良（n = 2）、心肌缺血（n = 1）。与 CPX 上没有“肺部受限”的难治性哮喘患者相比，吸入皮质类固醇（ICS）的剂量相似（中位数为 1300μg[四分位距（IQR）为 800-2000μg]与 1800μg[IQR 为 1000-2000μg]），并且在过去一年中接受的抢救口服类固醇疗程也相似（中位数为 5[1-6]与 5[1-6]）。在 CPX 后 6 个月，该组 ICS 剂量减少（中位数为 1300μg[IQR 为 800-2000μg]至 800μg[IQR 为 400-1000μg]；P<0.001），并且停用了其他药物治疗（n = 7）。CPX 后肺部受限的患者 ICS 剂量未改变，并且引入了其他治疗方法。
在难治性哮喘中，CPX 可以确认持续性运动性呼吸困难是由哮喘引起的，但也可以确定其他促成因素。非肺部受限的患者接受了过高剂量的类固醇治疗，CPX 可以确定呼吸困难的主要机制，从而有助于减少类固醇的使用。
