Variability of human upper airway collapsibility during sleep and the influence of body posture and sleep stage
MetadataShow full item record
The critical pressure at which the pharynx collapses (Pcrit) is an objective measurement of upper airway collapsibility, an important pathogenetic factor in obstructive sleep apnoea. This study examined the inherent variability of passive Pcrit measurement during sleep and evaluated the effects of sleep stage and body posture on Pcrit. Repeated measurements of Pcrit were assessed in 23 individuals (15 male) with diagnosed obstructive sleep apnoea throughout a single overnight sleep study. Body posture and sleep stage were unrestricted. Applied upper airway pressure was repetitively reduced to obtain multiple measurements of Pcrit. In 20 subjects multiple measurements of Pcrit were obtained. The overall coefficient of repeatability for Pcrit measurement was 4.1cm H 2O. Considering only the lateral posture, the coefficient was 4.8cm H 2O. It was 3.3cm H 2O in the supine posture. Pcrit decreased from the supine to lateral posture [supine mean 2.5cm H 2O, 95% confidence interval (CI) 1.4-3.6; lateral mean 0.3cm H 2O, 95% CI -0.8-1.4, P=0.007] but did not vary with sleep stage (P=0.91). This study has shown that the overall coefficient of repeatability was 4.1cm H 2O, implying that the minimum detectable difference, with 95% probability, between two repeated Pcrit measurements in an individual is 4.1cm H 2O. Such variability in overnight measures of Pcrit indicates that a single unqualified value of Pcrit cannot be used to characterize an individual's overall collapsibility during sleep. When within-subject variability is accounted for, change in body posture from supine to lateral significantly decreases passive pharyngeal collapsibility. © 2011 European Sleep Research Society.
Showing items related by title, author, creator and subject.
Examining the Relationship between Sleep Posture and Morning Spinal Symptoms in the Habitual Environment Using Infrared CamerasCary, Doug; Collinson, Roger; Sterling, M.; Briffa, Kathy (2016)Introduction: Sleeping is generally considered a period for rest and recovery, however some people wake with spinal symptoms not present on going to sleep and seek treatment. It has been clinically postulated that some ...
Bryant, Alan R. (2001)Hallux valgus and hallux limitus are two common foot pathologies that may require surgical intervention. While the modified Austin bunionectomy and the Youngswick osteotomy/cheilectomy respectively, are often used to ...
Evaluation of pharyngeal shape and size using anatomical optical coherence tomography in individuals with and without obstructive sleep apnoeaWalsh, J.; Leigh, M.; Paduch, A.; Maddison, K.; Philippe, D.; Armstrong, J.; Sampson, D.; Hillman, D.; Eastwood, Peter (2008)This study compared shape, size and length of the pharyngeal airway in individuals with and without obstructive sleep apnoea (OSA) using a novel endoscopic imaging technique, anatomical optical coherence tomography (aOCT). ...