The Effect of Mouth Closure on Airflow in OSA

Brigham and Women's Hospital66 enrolled

Overview

Mouth breathing is associated with increased airway resistance, pharyngeal collapsibility, and obstructive sleep apnea (OSA) severity. It is commonly believed that closing the mouth can mitigate the negative effects of mouth breathing during sleep. However, the investigators propose that mouth breathing serves as an essential route bypassing obstruction along the nasal route (e.g., velopharynx). The present study investigates the role of mouth breathing as an essential route in some OSA patients and its association with upper airway anatomical factors. Participants underwent drug-induced sleep endoscopy (DISE) with simultaneous pneumotach airflow measurements through the nose and mouth separately. During the DISE procedure, alternating mouth closure (every other breath) cycles were performed during flow-limited breathing. The investigators evaluated the overall effect mouth closure on inspiratory airflow, and the change in inspiratory airflow with mouth closure across three mouth-breathing quantiles. The investigators also evaluated if velopharyngeal obstruction was associated with mouth breathing and a negative airflow response to mouth closure.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Hypopnea, Sleep

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 89 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Diagnosed obstructive sleep apnea (AHI \> 5 events/h). * Scheduled to undergo clinical drug-induced sleep endoscopy. Exclusion Criteria: * pregnancy * age under 18 years * poor general health * allergy to propofol or dexmedetomidine * history of surgical treatment for sleep apnea, such as palate, tongue base, or epiglottis surgery.

Outcomes

Primary Outcomes

Total inspiratory flow

Change in airflow in the transition from mouth relaxed to mouth closed (intervention).

Time frame: 1 day - the intervention of mouth closure on the outcome is applied acutely on alternating breaths, such that the effect of mouth closure is assessed based on the experiment which occurs in a single day.

Secondary Outcomes

Change in total inspiratory airflow with mouth closure

We analyzed the change in total inspiratory flow within three quantiles of roughly equal sample sizes based on oral breathing; quantile 1: oral airflow \<0.05 L/min, quantile 2: oral airflow between 0.05 and 2.2 L/min, and quantile 3: oral airflow \>2.2 L/min. We also analyzed the effect of velopharyngeal obstruction on the change in total inspiratory airflow.

Time frame: 1 day - the intervention of mouth closure is applied acutely on alternating breaths, such that the effect of mouth closure on the outcome is assessed based on the experiment which occurs in a single day.