Changes in Pharyngeal Cross-Sectional Area with Posture and Application of Continuous Positive Airway Pressure in Patients with Obstructive Sleep Apnea
- 1 August 1987
- journal article
- research article
- Published by American Thoracic Society in American Review of Respiratory Disease
- Vol. 136 (3), 628-632
- https://doi.org/10.1164/ajrccm/136.3.628
Abstract
In an attempt to elucidate whether changes in posture (from sitting to supine) result in reduction in pharyngeal area, thus promoting pharyngeal occlusion during sleep in so predisposed persons, we studied 12 snoring apneic patients and 6 snoring nonapneic control subjects. in all subjects, we employed acoustic reflection technique to measure pharyngeal area at FRC sitting and supine. We also examined changes in pharyngeal area resulting from the application of positive intrapharyngeal pressure in sitting and supine posture. We found that (1) pharyngeal cross-sectional area at FRC was similar in both groups, (2) decrease in pharyngeal area with assumption of supine posture was also similar in both groups (21 +/- 11% in patients with OSA versus 15 +/- 13% in nonapneic control subjects), and (3) pharyngeal distensibility was significantly higher in apneic snorers than in nonapneic control subjects (0.090 +/- 0.039 cm H2O-1 in apneic snorers versus 0.032 +/- 0.027 cm H2O-1 in nonapneic control subjects; p less than 0.005). We conclude that changes in posture alone are not sufficient to convert a snorer into a patient with OSA; however, when physiologic abnormalities ("floppy" pharynx) are superimposed on postural reduction in pharyngeal area, airway occlusion results.Keywords
This publication has 3 references indexed in Scilit:
- Reproducibility and accuracy of airway area by acoustic reflectionJournal of Applied Physiology, 1984
- Lung Volume Dependence of Pharyngeal Cross-Sectional Area in Patients with Obstructive Sleep ApneaAmerican Review of Respiratory Disease, 1984
- Airway area by acoustic reflections measured at the mouthJournal of Applied Physiology, 1980