Related Experiment Video
Updated: Aug 9, 2026

Laryngeal Mask Airway (LMA) Placement in a Neonatal Patient Simulator Using a Non-Inflatable Supraglottic Airway (SGA)
Published on: July 14, 2023
Non-invasive positive pressure ventilation for laryngeal contraction disorder during sleep in multiple system atrophy
Michio Nonaka1, Tomihiro Imai, Tomoko Shintani
1Department of Neurology, Sapporo Medical University School of Medicine, Minami 1-Jo Nishi 16-Chome, Sapporo, Japan. mnonaka@sapmed.ac.jp
Abstract:
We examined the usefulness of non-invasive positive pressure ventilation (NPPV) in the management of nocturnal laryngeal stridor associated with vocal cord dysfunction in five cases of multiple system atrophy (MSA). First, the patients were investigated during sleep induced by a minimal dose of propofol. Laryngoscopy showed paradoxical vocal cord movement resulting in inspiratory stridor. Electromyographic (EMG) study revealed synchronized bursts in the thyroarytenoid muscles and diaphragm in every inspiratory phase whenever the stridor emerged. NPPV was initiated after paradoxical movement was recognized with laryngoscopy. The NPPV mask was equipped with an additional channel for laryngoscopic monitoring. The optimal pressure for treatment was determined according to laryngoscopic and EMG findings. Next, NPPV was applied to natural sleep using the conditions determined in propofol-induced sleep. In all cases, NPPV eliminated nocturnal stridor and oxygen desaturation during natural sleep. Laryngoscopic observation during induced sleep is recommended as a useful procedure to titrate the optimal pressure for NPPV therapy. Since central hypoventilation progresses in the course of MSA, the choice of NPPV rather than continuous positive airway pressure should be encouraged to treat laryngeal contraction disorder associated with MSA.
More Related Videos
Related Concept Videos
Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation (NIPPV)
Cardiopulmonary Resuscitation II: ACLS Airway Management
Cardiopulmonary Resuscitation V: Advanced Airway Management Techniques
Ventilatory Modes
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...
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...
Skeletal Muscle Relaxants: Therapeutic Uses

