Sleep Med Psychophysiol.
2000 Jun;7(1):18-26.
Airway Narrowing Patterns during Obstructive Sleep Apnea: Airway CT and Multi-level Airway Pressure Monitoring
- Affiliations
-
- 1Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
- 2Department of Orthodontics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Koea.
- 3Department of Neurology, Hallym University Hospital, Seoul, Korea.
Abstract
OBJECTIVES
To investigate the airway narrowing patterns by multi-level airway pressure (MAP) monitoring during sleep and to evaluate the value of CT scan taken during waking and sleep apneic periods to identify the level of airway narrowing (LAN) in patients with obstructive sleep apnea syndrome (OSAS).
METHODS
Eleven patients with OSAS underwent a night polysomnography with continuous MAP monitoring by 4-sensor (placed at nasopharynx, caudal-uvula, hypopharynx, esophagus) or 2-sensor (placed at caudal-uvula and esophagus) catheter. All patients had cine CT at five levels of high retro and alatal, low retropalatal, retroglossal, epiglottis and hypopharynx during awake and sleep periods. In each patient, LAN determained by CT scan (LANCT)during sleep apnea was compared with LAN by MAP monitoring (LANMAP).
RESULTS
Map monitoring showed that four patients (36%) had a single pattern of LAN while the other seven patients (64%) showed two or more different LANs in different apneic episodes. Velophrynx was the most common level of frequently observed airway narrowing during sleep apnea (636%). However, a single pattern of airway narrowing was more frequent (72.7%)in airway CT during sleep apnea. Velopharynx was the most common narrowest level also in apneic CT(66%). In comparing LANCT with LANMAP, the LANCT of five patients (45.5%) were high-concordant, those of another five (45.5%) low-concordant, and that of one (9%) discordant with LANMAP.
CONCLUSIONS
Cine CT scane during the awake state or sleep apnea may not reflect the LAN correctly in OSAS because most patients showed two or more different airway narrowing patterns during different episodes of sleep apnea in each patient.
