Determining Baseline Respiratory Duty Cycles in Subjects With and Without Airway Hyperresponsiveness
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 34
- 试验地点
- 2
- 主要终点
- Average inspiratory duty cycle in subjects without airway hyper-responsiveness
研究概览
简要总结
The study investigates the inspiratory duty cycle in subjects with and without airway hyper-responsiveness both at rest and during a bronchoprovocation challenge. The primary goal is to determine an average inspiratory duty cycle for standard use in the calculation of bronchoprovocation test results.
详细描述
At least fifteen subjects with airway hyper-responsiveness and fifteen without airway hyper-responsiveness will be recruited to participate in this randomized, crossover study. Subjects will complete 2 methacholine challenges at least 24 hours apart. One methacholine challenge will entail the volumetric method using a vibrating mesh nebulizer. The second methacholine challenge will be performed identically except that the nebulizer will be fitted onto an ultrasonic nebulizer so as to measure the inspiratory duty cycle throughout the bronchoprovocation challenge.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Must be 18 years of age or older
- •Participants with airway hyper-responsiveness must have a positive methacholine challenge
- •Forced expiratory volume (FEV1) of at least 65% of predicted (based on age, height, and gender)
- •Participants without airway hyper-responsiveness must have a negative methacholine challenge
- •All participants must avoid strenuous exercise on test days
- •No short-acting beta-2 agonist use within 6 hours of study visit
排除标准
- •Participants without known airway hyper-responsiveness cannot have a current or historical respiratory condition (e.g. asthma, allergic rhinitis)
- •Participants cannot be taking long-acting bronchodilators
- •Participants cannot be pregnant or lactating
- •Participants cannot have cardiovascular problems
结局指标
主要结局
Average inspiratory duty cycle in subjects without airway hyper-responsiveness
时间窗: 24 hours
The inspiratory duty cycles measured for each participant (in duplicate over at least 24 hours) will be averaged for all participants without airway hyper-responsiveness
Average inspiratory duty cycle in subjects with airway hyper-responsiveness measured using ultrasonic spirometer and tidal breathing
时间窗: 24 hours
The inspiratory duty cycles measured for each participant (in duplicate over at least 24 hours) will be averaged for all participants with airway hyper-responsiveness and for all participants without airway-hyperresponsiveness
次要结局
- Between-subject variability within subject group (i.e. airway hyper-responsiveness group)(1 hour)
- Within-subject variability in provocative dose of methacholine causing a 20% fall in forced expiratory volume (PD20) between repeat methacholine challenges(24 hours)
- Within-subject variability in inspiratory duty cycle measured using ultrasonic spirometer and tidal breathing during room air inhalation(24 hours)
- Variability in in inspiratory duty cycle between airway hyper-responsiveness group and group without airway-hyperresponsiveness(1 hour)
- Within-subject variability in inspiratory duty cycle measured using ultrasonic spirometer and tidal breathing during saline inhalation(24 hours)
- Variability in inspiratory duty cycle within subjects when inhaling room air versus an aerosol while using tidal breathing through an ultrasonic spirometer(1 hour)
- Variability in inspiratory duty cycle with progressive airway constriction induced through methacholine challenge testing(24 hours)
- Between-subject variability within subject group (no airway hyper-responsiveness group)(1 hour)
研究者
Don Cockcroft
Professor, Principal Investigator
University of Saskatchewan