The Effects of Positive Airway Pressure on the Mucolytic Effects of NAC (TEAM)

The goal of this clinical trial is to determine if positive pressure during inspiration will improve penetration of aerosolized N-Acetylcysteine (NAC) into airway mucus plugs in the lungs of patients with asthma or Chronic Obstructive Pulmonary Disease (COPD).

The main questions it aims to answer are:

• Does delivery of aerosolized NAC with positive inspiratory pressure have a greater effect on mucus plug burden in the lungs than delivery of NAC without positive pressure.
• Does delivery of aerosolized NAC with positive inspiratory pressure have a greater effect on lung function than delivery of NAC without positive pressure.

Participants will be assigned (in a single blind design) to the NAC via jet nebulizer group or the NAC via AeroEclipse-VersaPAP nebulizer group. Participants will each complete 5 treatment visits over the course of 30 days. Each treatment visit will consist of two treatments of a 10% NAC (3 mL) and 2.5 mg albuterol (0.5mL) inhalation solution separated by 4 hours, via the nebulization method specific to their group.

The optimal method for delivering aerosolized N-acetyl cysteine (NAC, Mucomyst) to the airways for the purpose of lysing mucus plugs is not established. The challenge is to ensure that the NAC aerosol penetrates the mucus plug to lyse it. We hypothesize that increasing the inspiratory pressure during aerosol inhalation will improve mixing of NAC with plugs and increase the chance of lysis within the time that the NAC liquid medication "dwells" in the plugged airway segment. Usual nebulizer systems that generate aerosols for inhalation do not allow for application of pressure during inspiration, but the VersaPAP system (from Monaghan Medical Corporation) has this capability. Specifically, the VersaPAP system combines continuous positive pressure during inspiration while the patient inhales aerosol medication, and the pressure will generate viscous fingers in the mucus plugs to aid lysis.

Recent published work from the Fahy lab has revealed that airway mucus plugs can be identified on low dose CT scans of the lungs and quantified using a bronchopulmonary segment based system to generate a measure that quantifies the mucus plug burden in the lung. This CT based mucus plug scoring system provides a predictive and monitoring biomarker for mucus plug pathology in the lungs of patients with asthma and COPD.

This is a single-blind phase 4 clinical trial designed to help determine the optimal method of delivery of aerosolized NAC to patients with mucus-associated lung disease (asthma and COPD). Subjects will be screened for evidence of mucus in their lungs as determined by CT imaging. Eligible participants will then be assigned to the NAC via jet nebulizer group or the NAC via AeroEclipse-VersaPAP nebulizer group and complete 5 treatment visits over the course of 30 days. Each treatment visit will consist of two treatments of a 10% NAC (3 mL) and 2.5 mg albuterol (0.5mL) inhalation solution separated by 4 hours, via the nebulization method specific to their group.