Epidemiology/etiology
- MC in overweight, middle-aged men
- Children with enlarged tonsils
- Smoking, alcohol
- Sedative drugs
Pathophysiology
- Apneas (>15) occur due to recurrent occlusion of the pharynx upon inspiration during sleep
- Inspiration results in negative pressure within the pharynx
- When awake, this is overcome by the action of dilating muscles of the upper airway (genioglossus + palatal muscles) – but they become hypotonic during sleep
- Partial narrowing causes snoring
- Complete occlusion causes apneas
- Apnea → hypoxia → ↑respiratory efforts → transiently wakes up the pt → allows dilating muscles to re-open the airway
Clinical features
- These awakenings are so brief that the patients can remain unaware of them – can be 100s of time per night
- Leads to sleep deprivation, daytime sleepiness, impaired intellectual performance
- Loud snoring
- Depression, irritability
Diagnosis
- Epworth Sleepiness Scale
- Overnight pulse oximetry
- EEG
- Dx of sleep apnea – >10-15 apneas in 1 hour of sleep
Treatment
- Correct treatable factors
- Lose weight
- CPAP delivered by mask during night
- It raises the pressure in the pharynx to keep the walls apart
- Advise patient not to drive