Related Experiment Video
Updated: Oct 20, 2025

Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics
Published on: April 19, 2024
Lung volume recruitment improves volitional airway clearance in amyotrophic lateral sclerosis
Stuart Cleary1, John E Misiaszek1, Sonya Wheeler2
1Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
Introduction/Aims:
In this study we evaluated the effects of lung volume recruitment treatment (LVR), a low-tech, low-cost, manual "breath-stacking" technique used to help people cough with enough force to clear their airways, thereby reducing the risk of aspiration and choking, on five volitional airway clearance and protection behaviors used by people living with amyotrophic lateral sclerosis (PwALS).
Methods:
Using a repeated-measures cross-over design, 29 PwALS performed five volitional airway clearance and protection behaviors in LVR treatment and in no-treatment, control conditions. Peak cough flow (PCF) was used to measure maximum expiratory rate during forced expiration, throat clearing, hawking, post-swallow coughing, and the supraglottic swallowing maneuver. Comparisons were made as a function of condition (treatment or control) and three time-points (pretreatment, and 15 and 30 minutes posttreatment).
Results:
LVR treatment had a significant positive effect on maximum expiratory rates during all tested airway clearance and protection behaviors. Increased PCF values lasted for up to 30 minutes post-LVR for all tested behaviors in the treatment condition.
Discussion:
We found that LVR treatment could increase control over airway clearance in PwALS, as well as provide improved airway protection for up to 30 minutes, the duration of a typical meal. This study has implications for patient care. These include offering patients control over some of the most feared symptoms of ALS, particularly choking during activities of daily living, and enhanced ALS respiratory care in low-resource settings. Findings may have implications for other neurodegenerative disorders in which dysphagia occurs with retained sensory function.
More Related Videos
Related Concept Videos
Respiratory Volumes
Tidal Volume (TV) Tidal volume (TV) is the air inhaled or exhaled in a...
Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...
Cardiopulmonary Resuscitation II: ACLS Airway Management
Respiratory Volumes and Capacities I
Respiratory Volumes and Capacities
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...

