Glottic aperture and effective minute ventilation during nasal two-level positive pressure ventilation in spontaneous mode | JoVE Visualize

Glottic aperture and effective minute ventilation during nasal two-level positive pressure ventilation in spontaneous mode

V F Parreira¹, P Delguste, V Jounieaux

¹Pneumology Unit, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium.

American Journal of Respiratory and Critical Care Medicine|December 1, 1996

View abstract on PubMed

Summary

Nasal mask non-invasive positive pressure ventilation (nIPPV) at 20 cm H2O inspiratory pressure increased effective minute ventilation. The glottis played no significant role in controlling ventilation during nIPPV in awake subjects.

Area of Science:

Respiratory Physiology
Mechanical Ventilation

Background:

Non-invasive positive pressure ventilation (nIPPV) is used to support breathing.
Understanding glottic function during nIPPV is crucial for optimizing ventilation strategies.

Purpose of the Study:

To investigate glottic behavior and its impact on effective minute ventilation during nIPPV.
To evaluate the effects of increasing inspiratory positive airway pressure (IPAP) levels on ventilation.

Main Methods:

Ten awake subjects received nIPPV via nasal mask at IPAP levels of 10, 15, and 20 cm H2O (EPAP 4 cm H2O).
Glottic behavior was monitored using fiberoptic bronchoscopy.
Tidal volume, respiratory frequency, and other respiratory parameters were measured.

Main Results:

Effective minute ventilation increased only at 20 cm H2O IPAP compared to spontaneous breathing.
Increased IPAP led to decreased respiratory frequency, offsetting tidal volume increases at lower pressures.
Glottic function did not appear to influence effective minute ventilation during nIPPV.

Conclusions:

Higher IPAP levels (20 cm H2O) are needed to significantly improve effective minute ventilation with nIPPV in awake subjects.
The glottis does not play a significant role in regulating ventilation during nIPPV, unlike in controlled ventilation modes.
Breathing pattern changes, particularly reduced respiratory frequency, contribute to improved alveolar ventilation during nIPPV.