TY - JOUR
T1 - Upper airway collapsibility measured using a simple wakefulness test closely relates to the pharyngeal critical closing pressure during sleep in obstructive sleep apnea
AU - Osman, Amal M.
AU - Carberry, Jayne C.
AU - Burke, Peter G. R.
AU - Toson, Barbara
AU - Grunstein, Ronald R.
AU - Eckert, Danny J.
PY - 2019/4/23
Y1 - 2019/4/23
N2 - Study Objectives: A collapsible or crowded pharyngeal airway is the main cause of obstructive sleep apnea (OSA). However, quantification of airway collapsibility during sleep (Pcrit) is not clinically feasible. The primary aim of this study was to compare upper airway collapsibility using a simple wakefulness test with Pcrit during sleep. Methods: Participants with OSA were instrumented with a nasal mask, pneumotachograph and two pressure sensors, one at the choanae (PCHO), the other just above the epiglottis (PEPI). Approximately 60 brief (250 ms) pulses of negative airway pressure (~ -12 cmH2O at the mask) were delivered in early inspiration during wakefulness to measure the upper airway collapsibility index (UACI). Transient reductions in the continuous positive airway pressure (CPAP) holding pressure were then performed during sleep to determine Pcrit. In a subset of participants, the optimal number of replicate trials required to calculate the UACI was assessed. Results: The UACI (39 ± 24 mean ± SD; range = 0%-87%) and Pcrit (-0.11 ± 2.5; range: -4 to +5 cmH2O) were quantified in 34 middle-aged people (9 female) with varying OSA severity (apnea-hypopnea index range = 5-92 events/h). The UACI at a mask pressure of approximately -12 cmH2O positively correlated with Pcrit (r = 0.8; p < 0.001) and could be quantified reliably with as few as 10 replicate trials. The UACI performed well at discriminating individuals with subatmospheric Pcrit values [receiver operating characteristic curve analysis area under the curve = 0.9 (0.8-1), p < 0.001]. Conclusions: These findings indicate that a simple wakefulness test may be useful to estimate the extent of upper airway anatomical impairment during sleep in people with OSA to direct targeted non-CPAP therapies for OSA.
AB - Study Objectives: A collapsible or crowded pharyngeal airway is the main cause of obstructive sleep apnea (OSA). However, quantification of airway collapsibility during sleep (Pcrit) is not clinically feasible. The primary aim of this study was to compare upper airway collapsibility using a simple wakefulness test with Pcrit during sleep. Methods: Participants with OSA were instrumented with a nasal mask, pneumotachograph and two pressure sensors, one at the choanae (PCHO), the other just above the epiglottis (PEPI). Approximately 60 brief (250 ms) pulses of negative airway pressure (~ -12 cmH2O at the mask) were delivered in early inspiration during wakefulness to measure the upper airway collapsibility index (UACI). Transient reductions in the continuous positive airway pressure (CPAP) holding pressure were then performed during sleep to determine Pcrit. In a subset of participants, the optimal number of replicate trials required to calculate the UACI was assessed. Results: The UACI (39 ± 24 mean ± SD; range = 0%-87%) and Pcrit (-0.11 ± 2.5; range: -4 to +5 cmH2O) were quantified in 34 middle-aged people (9 female) with varying OSA severity (apnea-hypopnea index range = 5-92 events/h). The UACI at a mask pressure of approximately -12 cmH2O positively correlated with Pcrit (r = 0.8; p < 0.001) and could be quantified reliably with as few as 10 replicate trials. The UACI performed well at discriminating individuals with subatmospheric Pcrit values [receiver operating characteristic curve analysis area under the curve = 0.9 (0.8-1), p < 0.001]. Conclusions: These findings indicate that a simple wakefulness test may be useful to estimate the extent of upper airway anatomical impairment during sleep in people with OSA to direct targeted non-CPAP therapies for OSA.
KW - phenotyping
KW - respiratory physiology
KW - sleep-disordered breathing
KW - upper airway anatomy
UR - http://www.scopus.com/inward/record.url?scp=85068916683&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/nhmrc/1116942
UR - http://purl.org/au-research/grants/nhmrc/1060992
UR - http://purl.org/au-research/grants/nhmrc/1042493
U2 - 10.1093/sleep/zsz080
DO - 10.1093/sleep/zsz080
M3 - Article
VL - 42
SP - 1
EP - 10
JO - Sleep
JF - Sleep
SN - 0161-8105
IS - 7
M1 - zsz080
ER -