Obstructive sleep apnoea (OSA) is a disorder characterised by episodes of apnoea (temporary cessation of breathing) during sleep.
Pathophysiology
It is caused by complete or partial upper airway obstruction during sleep. This is due to collapse of the pharyngeal airway due to loss of neural tone as well as the loss of positive pressure keeping it patent.
⚠️ Risk factors
- Middle age
- Male
- Obesity
- Alcohol
- Smoking
😷 Presentation
- Snoring
- Apnoea during sleep - usually reported by the partner. Breathing recommences when the individual is woken or aroused.
- Morning headaches and feeling tired in the morning
- Daytime sleepiness - patients who need to be fully awake for their work require urgent referral to ensure safety. The DVLA should be informed if it is causing excessive daytime sleepiness.
- Concentration problems
- Hypoxaemia during sleep
Inadequate oxygenation activates the sympathetic nervous system which can increase the risk of hypertension, heart failure and increase risk of MI and stroke in severe cases.
🔍 Investigations
- Polysomnography - a “sleep study” that is currently the gold-standard test. It requires the patient being monitored throughout the night, assessing for apnoea and hypopnoeas to determine their Apnoea-Hypopnoea index (AHI).
We can assess sleepiness of the patient using the Epworth Sleepiness Scale. This is to be completed by the patient or partner.
Another test that can be completed is the Multiple Sleep Latency Test (MSLT) which assesses the time taken to fall asleep in a dark room according to EEG.
🧰 Management
- 🥇 ENT or specialist sleep clinic referral to perform the aforementioned polysomnography.
- 🥇 Lifestyle advice - such as losing weight, alcohol and smoking cessation.
- Continuous positive airway pressure (CPAP) during sleep to maintain airway patency. This is first-line for moderate-severe OSA.
- Surgery - this is of course a last-line option for patients with significant impact on their quality of life. The most common procedure is a uvulopalatopharyngoplasty (UPPP)
