Clinical trial NCT04001465: Determining Baseline Respiratory Duty Cycles in Subjects With and Without Airway Hyperresponsiveness
Official title: Determining Baseline Respiratory Duty Cycles in Subjects With and Without Airway Hyperresponsiveness
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Airway Hyper Responsiveness
Lead sponsor: University of Saskatchewan
Sponsor class: OTHER
First posted: 2019-06-28
Enrollment: 34
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Average inspiratory duty cycle in subjects with airway hyper-responsiveness measured using ultrasonic spirometer and tidal breathing
timeFrame: 24 hours
measure: Average inspiratory duty cycle in subjects without airway hyper-responsiveness
timeFrame: 24 hours
Secondary outcomes:
measure: Within-subject variability in inspiratory duty cycle measured using ultrasonic spirometer and tidal breathing during room air inhalation
timeFrame: 24 hours
measure: Between-subject variability within subject group (i.e. airway hyper-responsiveness group)
timeFrame: 1 hour
measure: Variability in inspiratory duty cycle within subjects when inhaling room air versus an aerosol while using tidal breathing through an ultrasonic spirometer
timeFrame: 1 hour
measure: Within-subject variability in provocative dose of methacholine causing a 20% fall in forced expiratory volume (PD20) between repeat methacholine challenges
timeFrame: 24 hours
measure: Variability in inspiratory duty cycle with progressive airway constriction induced through methacholine challenge testing
timeFrame: 24 hours
measure: Variability in in inspiratory duty cycle between airway hyper-responsiveness group and group without airway-hyperresponsiveness
timeFrame: 1 hour
measure: Within-subject variability in inspiratory duty cycle measured using ultrasonic spirometer and tidal breathing during saline inhalation
timeFrame: 24 hours
measure: Between-subject variability within subject group (no airway hyper-responsiveness group)
timeFrame: 1 hour
Other outcomes:
Locations:
city: Saskatoon
country: Canada
facility: Asthma Research Lab - University of Saskatchewan
state: Saskatchewan
Study officials:
affiliation: University of Saskatchewan
name: Don Cockcroft, MD
role: PRINCIPAL_INVESTIGATOR
References: