Simon A Joosten1,2, Scott A Sands3, Bradley A Edwards4,3, Kais Hamza5, Anthony Turton1, Kenneth K Lau6, Marcus Crossett6, Philip J Berger2, Garun S Hamilton1,7. 1. Monash Lung and Sleep, Monash Health, Monash Medical Centre, Melbourne, Australia. 2. Ritchie Centre, Monash Institute of Medical Research, Monash University, Melbourne, Australia. 3. Division of Sleep Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA. 4. Department of Physiology and School of Psychological Sciences, Monash University, Melbourne, Australia. 5. School of Mathematical Sciences, Monash University, Melbourne, Australia. 6. Department of Diagnostic Imaging, Monash Health, Melbourne, Australia. 7. School of Clinical Sciences, Monash University, Melbourne, Australia.
Abstract
BACKGROUND AND OBJECTIVE: This study aimed to evaluate the involvement of airway cross-sectional area and shape, and functional residual capacity (FRC), in the genesis of obstructive sleep apnoea (OSA) in patients with supine-predominant OSA. METHODS: Three groups were recruited: (i) supine OSA, defined as a supine apnoea-hyponoea index (AHI) at least twice that of the non-supine AHI; (ii) rapid eye movement (REM) OSA, defined as REM AHI at least twice the non-REM AHI and also selected to have supine AHI less than twice that of the non-supine AHI (i.e. to be non-positional); and (iii) no OSA, defined as an AHI less than five events per hour. The groups were matched for age, gender and body mass index. Patients underwent four-dimensional computed tomography scanning of the upper airway in the supine and lateral decubitus positions. FRC was measured in the seated, supine and lateral decubitus positions. RESULTS: Patients with supine OSA demonstrated a significant decrease in FRC of 340 mL (P = 0.026) when moving from the lateral to supine position compared to controls with no OSA, and REM OSA patients. We found no differences between groups in upper airway size and shape. However, all groups showed a significant change in airway shape with the velopharyngeal airway adopting a more elliptoid shape (with the long axis laterally oriented), with reduced anteroposterior diameter in the supine position. CONCLUSIONS: A fall in FRC when moving lateral to supine in supine OSA patients may be an important triggering factor in the generation of OSA in this patient group.
BACKGROUND AND OBJECTIVE: This study aimed to evaluate the involvement of airway cross-sectional area and shape, and functional residual capacity (FRC), in the genesis of obstructive sleep apnoea (OSA) in patients with supine-predominant OSA. METHODS: Three groups were recruited: (i) supine OSA, defined as a supine apnoea-hyponoea index (AHI) at least twice that of the non-supine AHI; (ii) rapid eye movement (REM) OSA, defined as REM AHI at least twice the non-REM AHI and also selected to have supine AHI less than twice that of the non-supine AHI (i.e. to be non-positional); and (iii) no OSA, defined as an AHI less than five events per hour. The groups were matched for age, gender and body mass index. Patients underwent four-dimensional computed tomography scanning of the upper airway in the supine and lateral decubitus positions. FRC was measured in the seated, supine and lateral decubitus positions. RESULTS:Patients with supine OSA demonstrated a significant decrease in FRC of 340 mL (P = 0.026) when moving from the lateral to supine position compared to controls with no OSA, and REM OSA patients. We found no differences between groups in upper airway size and shape. However, all groups showed a significant change in airway shape with the velopharyngeal airway adopting a more elliptoid shape (with the long axis laterally oriented), with reduced anteroposterior diameter in the supine position. CONCLUSIONS: A fall in FRC when moving lateral to supine in supine OSA patients may be an important triggering factor in the generation of OSA in this patient group.
Authors: Melania Marques; Pedro R Genta; Scott A Sands; Ali Azarbazin; Camila de Melo; Luigi Taranto-Montemurro; David P White; Andrew Wellman Journal: Sleep Date: 2017-03-01 Impact factor: 5.849
Authors: Simon A Joosten; Shane A Landry; Scott A Sands; Philip I Terrill; Dwayne Mann; Christopher Andara; Elizabeth Skuza; Anthony Turton; Philip Berger; Garun S Hamilton; Bradley A Edwards Journal: Respirology Date: 2017-07-20 Impact factor: 6.424
Authors: Raichel M Alex; Tamar Sofer; Ali Azarbarzin; Daniel Vena; Laura K Gell; Andrew Wellman; David P White; Susan Redline; Scott A Sands Journal: Sleep Date: 2022-09-08 Impact factor: 6.313
Authors: Simon A Joosten; Michael Tan; Ai-Ming Wong; Shane A Landry; Paul Leong; Scott A Sands; Caroline Beatty; Luke Thomson; Jeremy Stonehouse; Anthony Turton; Garun S Hamilton; Bradley A Edwards Journal: J Clin Sleep Med Date: 2021-03-01 Impact factor: 4.062