Single and multiple breath nitrogen washout compared with the methacholine test in patients with suspected asthma and normal spirometry

IF 3.6 3区医学 Q1 RESPIRATORY SYSTEM

BMJ Open Respiratory Research Pub Date : 2024-05-01 DOI:10.1136/bmjresp-2023-001919

Aline Stalder Siebeneichler, Desiree M Schumann, Meropi Karakioulaki, Nora Brachsler, Andrei M Darie, Leticia Grize, Thiago G Heck, Michael Tamm, Philipp Latzin, Daiana Stolz

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引用次数: 0

Abstract

Background Methods used to assess ventilation heterogeneity through inert gas washout have been standardised and showed high sensitivity in diagnosing many respiratory diseases. We hypothesised that nitrogen single or multiple breath washout tests, respectively nitrogen single breath washout (N2SBW) and nitrogen multiple breath washout (N2MBW), may be pathological in patients with clinical suspicion of asthma but normal spirometry. Our aim was to assess whether N2SBW and N2MBW are associated with methacholine challenge test (MCT) results in this population. We also postulated that an alteration in SIII at N2SBW could be detected before the 20% fall of forced expiratory volume in the first second (FEV1) in MCT. Study design and methods This prospective, observational, single-centre study included patients with suspicion of asthma with normal spirometry. Patients completed questionnaires on symptoms and health-related quality-of-life and underwent the following lung function tests: N2SBW (SIII), N2MBW (Lung clearance index (LCI), Scond, Sacin), MCT (FEV1 and sGeff) as well as N2SBW between each methacholine dose. Results 182 patients were screened and 106 were included in the study, with mean age of 41.8±14 years. The majority were never-smokers (58%) and women (61%). MCT was abnormal in 48% of participants, N2SBW was pathological in 10.6% at baseline and N2MBW abnormality ranged widely (LCI 81%, Scond 18%, Sacin 43%). The dose response rate of the MCT showed weak to moderate correlation with the subsequent N2SBW measurements during the provocation phases (ρ 0.34–0.50) but no correlation with N2MBW. Conclusions Both MCT and N2 washout tests are frequently pathological in patients with suspicion of asthma with normal spirometry. The weak association and lack of concordance across the tests highlight that they reflect different but not interchangeable pathological pathways of the disease. Data are available upon reasonable request.

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疑似哮喘且肺活量正常患者的单次和多次呼气氮气冲洗与甲基胆碱试验的比较

背景通过惰性气体冲洗来评估通气异质性的方法已经标准化，在诊断许多呼吸系统疾病时显示出很高的灵敏度。我们假设，氮气单次或多次呼气冲洗试验（分别为氮气单次呼气冲洗（N2SBW）和氮气多次呼气冲洗（N2MBW））可能会对临床怀疑为哮喘但肺活量正常的患者产生病理影响。我们的目的是评估 N2SBW 和 N2MBW 是否与这一人群的甲基胆碱挑战试验（MCT）结果相关。我们还推测，在 MCT 中第一秒用力呼气容积（FEV1）下降 20% 之前，可以检测到 N2SBW 时 SIII 的变化。研究设计和方法这项前瞻性、观察性、单中心研究纳入了肺活量正常的哮喘疑似患者。患者填写了有关症状和健康相关生活质量的问卷，并接受了以下肺功能测试：N2SBW (SIII)、N2MBW (肺清除指数 (LCI)、Scond、Sacin)、MCT (FEV1 和 sGeff) 以及每次服用甲卡胆碱之间的 N2SBW。结果筛选出 182 名患者，106 名纳入研究，平均年龄（41.8±14）岁。大多数患者从不吸烟（58%），女性（61%）。48% 的参与者 MCT 异常，10.6% 的基线 N2SBW 异常，N2MBW 异常的范围很广（LCI 81%，Scond 18%，Sacin 43%）。在激发阶段，MCT 的剂量反应率与随后的 N2SBW 测量值呈弱到中等程度的相关性（ρ 0.34-0.50），但与 N2MBW 没有相关性。结论在肺活量正常的哮喘疑似患者中，MCT 和 N2 冲洗试验都经常是病理性的。这两项检测之间的关联性较弱且缺乏一致性，这突出表明它们反映了疾病的不同病理途径，但不能相互替代。如有合理要求，可提供相关数据。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

BMJ Open Respiratory Research RESPIRATORY SYSTEM-

CiteScore

6.60

自引率

2.40%

发文量

审稿时长

12 weeks

期刊介绍： BMJ Open Respiratory Research is a peer-reviewed, open access journal publishing respiratory and critical care medicine. It is the sister journal to Thorax and co-owned by the British Thoracic Society and BMJ. The journal focuses on robustness of methodology and scientific rigour with less emphasis on novelty or perceived impact. BMJ Open Respiratory Research operates a rapid review process, with continuous publication online, ensuring timely, up-to-date research is available worldwide. The journal publishes review articles and all research study types: Basic science including laboratory based experiments and animal models, Pilot studies or proof of concept, Observational studies, Study protocols, Registries, Clinical trials from phase I to multicentre randomised clinical trials, Systematic reviews and meta-analyses.