Use of flow-volume curves to predict oral appliance treatment outcome in obstructive sleep apnea.

Abstract

BACKGROUND:

It has been recognized that mandibular advancement splint (MAS) treatment is effective in some, but not all, patients with obstructive sleep apnea (OSA). Hence there is a need for a simple and reliable clinical tool to assist in the differentiation of treatment responses. We hypothesized that abnormalities of flow-volume curves, together with other clinical variables, may have clinical utility in the prediction of MAS treatment outcome.

METHODS:

Fifty-four patients with known OSA underwent MAS treatment. Expiratory and inspiratory flow-volume curves were measured in the erect and supine positions to derive midinspiratory flow (MIF(50)) and the ratio of expiratory to inspiratory flow at 50% of vital capacity (MEF(50):MIF(50)). Multivariable logistic regression was performed to identify additional significant clinical variables in the prediction of treatment outcome.

RESULTS:

The mean (+/- SD) apnea-hypopnea index (AHI) in 35 responders was significantly reduced from 28.9 +/- 13.7 to 6.7 +/- 5.8/hour (p<0.001). In 19 nonresponders there was no significant change in AHI. MIF(50) was lower (6.04 +/- 1.80 vs. 6.88 +/- 1.08 L/second; p=0.035) and the MEF(50):MIF(50) ratio was higher (0.82 +/- 0.23 vs. 0.61 +/- 0.15; p=0.001) in responders than nonresponders. Logistic regression analysis revealed that the MEF(50):MIF(50) ratio was the most important predictive factor for MAS treatment outcome, but that body mass index, age, and baseline AHI were also contributory.

CONCLUSIONS:

These data suggest that flow-volume curves, in combination with other factors such as body mass index, age, and baseline AHI, may have a useful clinical role in the prediction of treatment outcome with MAS.

• Authors: Biao Zeng, Andrew T Ng, M Ali Darendeliler, Peter Petocz, Peter A Cistulli
• Journal: American journal of respiratory and critical care medicine (Am J Respir Crit Care Med) Vol. 175 Issue 7 Pg. 726-30 (Apr 01 2007) ISSN: 1073-449X [Print] United States
• PMID: 17218619 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Adult
• Female
• Humans
• Male
• Mandibular Advancement (instrumentation)
• Middle Aged
• Orthodontic Appliances, Removable
• Predictive Value of Tests
• Pulmonary Ventilation (physiology)
• ROC Curve
• Sleep Apnea, Obstructive (physiopathology, therapy)
• Spirometry
• Total Lung Capacity (physiology)
• Treatment Outcome