All posts tagged 28th November

• obstructive sleep apnoea/hyponea syndrome can be defined as the co-existence of excessive daytime sleepiness and irregular breathing at night
• repeated collapse of upper airway during sleep causing cessation of breathing despite inspiratory effort
• obstruction may be complete, with total obstruction of the airway (apnoea) or partial (hypopnoea) causing hypoventilation
• severity measured using the apnoea/hyponoea index (AHI)

• overweight
• smoker
• alcohol
• sedatives
• older age group
• hypothyroidism

Nocturnal symptoms

• loud snoring, majority of snorers do not have OSA
• choking and restlessness
• nocturia
• tiredness, headaches, impaired quality of life and social life, depression and hypersomnolence (falling asleep at inappropriate times) – 24% of people with OSA reported to fall asleep whilst driving at least weekly
• nocturnal hypoxaemia if prolonged causes hypertension and cardiac problems

Diurnal symptoms

Medical symptoms

• history from pt and sleeping partner
• overnight polysomnography in sleep laboratory or at home, measurements include traces of heart, brain and respiratory activity, oral and nasal airflow as well as sounds and body position
• subjective assessment of daytime sleepiness using the Epworth Sleepiness Scale

• multidisciplinary care: involves respiratory/thoracic physicians, ENT, Maxillo-Facial surgeons and orthodontists

Management options involve:

• behavioural modification – weight loss programmes, alcohol avoidance, alteration of sleeping position
• eliminate aggravating factors – control of chronic obstructive airway disease, asthma, hypothyroidism

Non-surgical options:

• continuous positive airway pressure (CPAP) delivers continuous air under pressure via tight fitting nasal mask (considered gold standard treatment); disadvantages – noisy, cumbersome and efficacy highly reliant on pt compliance
• mandibular advancement appliances (MAA) offered as alternative to pts who cannot tolerate CPAP
• review suggests MMAs have similar treatment efficacy for mild-moderate OSA as CPAP

Surgical options sometimes considered:

• mandibular or bimaxillary advancement surgery
• surgery to reposition hyoid
• surgical correction of nasal and naso-pharyngeal obstructions (septal deviation, polpys etc)

• primary action – to increase and stabilize the oropharyngeal and/or hypopharyngeal airway space
• many designs described, include vacuum formed devices, CoCr, cribbed activator, removable Herbst with intermaxillary elastics; 1 or 2 piece or adjustable appliances
• resemble functional appliance with protrusive bite (75% maximum protrusion suggested) and as little vertical opening as possible
• efficacy review identified 14 good quality trials compared MAAs of varying design with inactive devices or other MAAs in mostly mild-moderate OSA pts:

- all MAAs improved AHI

- comparison with inactive appliances and found that mandibular protrusion is crucial

- evidence for specific designs being more effective that others is conflicting, more research is required

• compliance rate of 52-100% reported