Related Experiment Video
Updated: Mar 21, 2026

Preoxygenation Techniques for Tracheal Intubation in Critically Ill Adults Utilizing Oxygen Mask and Noninvasive Ventilation
Published on: December 5, 2025
Impact of Acute Changes in CPAP Flow Route in Sleep Apnea Treatment
Rafaela G S Andrade1, Fernanda Madeiro1, Vivien S Piccin1
1Sleep Laboratory, Pulmonary Division, Heart Institute, University of São Paulo, São Paulo, Brazil.
Background:
CPAP is the gold standard treatment for OSA and was conceived to be applied through a nasal interface. This study was designed to determine the acute effects of changing the nasal CPAP route to oronasal and oral in upper airway patency during sleep in patients with OSA. We hypothesized that the oronasal route may compromise CPAP's effectiveness in treating OSA.
Methods:
Eighteen patients (mean ± SD age, 44 ± 9 years; BMI, 33.8 ± 4.7 kg/m2; apnea-hypopnea index, 49.0 ± 39.1 events/hour) slept with a customized oronasal mask with nasal and oral sealed compartments connected to a multidirectional valve. Sleep was monitored by using full polysomnography and induced by low doses of midazolam. Nasal CPAP was titrated up to holding pressure. Flow route was acutely changed to the oronasal (n = 18) and oral route (n = 16) during sleep. Retroglossal area was continuously observed by using nasoendoscopy.
Results:
Nasal CPAP (14.8 ± 4.1 cm H2O) was able to stabilize breathing in all patients. In contrast, CPAP delivered by the oronasal and oral routes promoted obstructive events in 12 (66.7%) and 14 (87.5%) patients, respectively. Compared with stable breathing during the nasal route, there was a significant and progressive reduction in the distance between the epiglottis and tongue base and the retroglossal area when CPAP was delivered by the oronasal and oral routes.
Conclusions:
CPAP delivered through the oronasal route may compromise CPAP's effectiveness in treating OSA.
More Related Videos
Related Concept Videos
Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation...
Sleep Apnea
The condition is more prevalent among...
Administering Oxygen by Nasal Cannula
Nasal Cannulas
A nasal cannula is a lightweight tube split into two prongs placed in the nostrils,...
Cardiopulmonary Resuscitation II: ACLS Airway Management
Oxygen Delivering System I: Nasal Cannula and Face Mask
Nasal Cannula
A nasal cannula is a lightweight tube split at one end into two prongs and placed in the nostrils. It is typically used to deliver low to medium levels of oxygen.
Suggested flow rate: The suggested flow rate for a nasal cannula typically ranges between 1 and 6 L/min.
Oxygen percentage setting:...
Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue,...

