NCT07531901

Evaluating the Feasibility and Reliability of Using Handheld Nebulizers to Conduct Cough Sensitivity Testing With Citric Acid

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 10 (estimated)
• Sponsor: University of Montana · Academic / Other
• Sex: All
• Age: 18 Years – 89 Years
• Healthy volunteers: Accepted

Summary

Objective cough reflex sensitivity testing is typically restricted to specialized research laboratories due to reliance on expensive dosimeter-controlled aerosol delivery systems. This study evaluates the feasibility and reliability of a low-cost alternative method using a handheld nebulizer for citric acid cough challenge testing. Healthy adult participants will complete cough reflex sensitivity testing using both a standard dosimeter-controlled nebulizer system (Cosmed QuarkSpiro) and a handheld nebulizer (DeVilbiss 45). The study will compare cough threshold outcomes between methods to determine whether handheld nebulizer-based testing produces comparable and reproducible measurements.

Detailed description

Cough reflex sensitivity testing is widely used in respiratory research to quantify airway sensory responsiveness. Traditional testing protocols use dosimeter-controlled nebulizer systems to deliver precise concentrations of aerosolized tussive agents such as citric acid. However, these systems are costly and require specialized laboratory infrastructure, limiting access to objective cough testing in outpatient and community-based settings. This study investigates the feasibility and reliability of using a commercially available handheld nebulizer as a low-cost alternative for cough reflex sensitivity testing. Healthy adult volunteers will undergo standardized cough challenge testing using citric acid delivered through two aerosol delivery systems: a laboratory dosimeter-controlled nebulizer (Cosmed QuarkSpiro) and a handheld nebulizer (DeVilbiss 45). The primary outcomes will be cough threshold measures (e.g., C2 and C5), defined as the citric acid concentration that elicits two or five coughs. Participants will complete testing sessions using both delivery methods under controlled conditions. Findings from this proof-of-concept study will inform future research aimed at expanding access to objective cough assessment in clinical and community settings.

Conditions

• Cough Reflex Sensitivity

Interventions

Type	Name	Description
DEVICE	Cosmed QuarkSpiro Dosimeter-Controlled Nebulizer	Laboratory spirometry system equipped with a dosimeter-controlled nebulizer used to deliver standardized aerosolized citric acid during cough challenge testing.
DEVICE	DeVilbiss 45 Handheld Nebulizer	Commercial handheld nebulizer used to deliver aerosolized citric acid during cough challenge testing.

Timeline

• Start date: 2026-05-01
• Primary completion: 2027-02-01
• Completion: 2027-02-01
• First posted: 2026-04-15
• Last updated: 2026-04-15