Describe the pathophysiology of the Obstructive Sleep Apnoea Syndrome.
What are the potential long-term complications of this syndrome?
(a) Patency of the oropharyngeal airway is due to activity of paired sets of upper airway muscles.
The presence of respiratory activity in the muscles of the soft palate, pharyngeal walls and tongue prevents otherwise floppy strictures from being sucked into the airway. Obstruction during sleep may be due to a combination of factors:
1) reduced airways size -enlarged tonsils/adenoids, macroglossia myxoedema, acromegaly, malignancy. A large percentage of OSA patients have a structurally small airway.
2) neuromuscular tone- reduced tone occurs in REM sleep, particularly in postural muscles of the pharynx, palate etc.
3) neuromuscular coordination – the normal coordination of increased upper airway tone withinspiration is lost.
(b) Potential long-term complications include:
Cardiac- hypertension, nocturnal angina/arrhythmias
Pulmonary- respiratory failure, cor pulmonale
Neurological- headache, somnolence, dementia
Psychiatric – depression, personality changes
Other - impotence, polycythaemia, glaucoma
Pathophysiology of sleep apnoea:
Consequences of sleep apnoea
Malhotra, Atul, and David P. White. "Obstructive sleep apnoea." The lancet360.9328 (2002): 237-245.
SHEPARD Jr, J. O. H. N. "Cardiopulmonary consequences of obstructive sleep apnea." Mayo Clinic Proceedings. Vol. 65. No. 9. Elsevier, 1990.
Peter, J. H., et al. "Manifestations and consequences of obstructive sleep apnoea." European Respiratory Journal 8.9 (1995): 1572-1583.
Balachandran, Jay S., and Sanjay R. Patel. "Obstructive Sleep Apnea." Annals of internal medicine 161.9 (2014): ITC1-ITC1.
Jordan, Amy S., David G. McSharry, and Atul Malhotra. "Adult obstructive sleep apnoea." The Lancet 383.9918 (2014): 736-747.
Park, John G., M. D. KANNAN RAMAR, and ERIC J. OLs0N. "Updates on Definition, Consequences, and Management of Obstructive Sleep Apnea." (2011).
American Academy of Sleep Medicine. European Respiratory Society. Australasian Sleep Association. American Thoracic Society "Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research: the report of an American Academy of Sleep Medicine Task Force." Sleep. 1999;22:667-689
Fogel, R. B., A. Malhotra, and D. P. White. "Sleep· 2: pathophysiology of obstructive sleep apnoea/hypopnoea syndrome." Thorax 59.2 (2004): 159-163.
Young, Terry, James Skatrud, and Paul E. Peppard. "Risk factors for obstructive sleep apnea in adults." Jama 291.16 (2004): 2013-2016.