Sleep Apnoea

Obstructive Sleep Apnoea

This is a condition where the walls of the airway briefly collapse during sleep.

This obstructs the airway causing cessation of breathing during sleep (apnoea) followed by partial arousal to regain breath.

The patient then falls asleep again and the cycle repeats itself.

It can lead to pulmonary hypertension and type II respiratory failure.

It is classically seen in middle-aged obese men who complain of loud snoring.

Risk factors

Obesity

Large tonsils

Large tongue (macroglossia)

Symptoms

Loud snoring

Lethargy with daytime napping

Morning headache

Decreased libido

Hypertension

Compensated respiratory acidosis

Key tests

Epworth sleepiness scale – a questionnaire which is used as a screening test to identify sleepiness secondary to poor sleep. If the score is high, refer to sleep clinic.

Polysomnography – this is diagnostic and involves monitoring the SpO2, EEG and airflow during sleep

Management

Encourage weight loss and avoidance of tobacco/alcohol

CPAP via nasal mask during sleep – this prevents collapse of the airway

Intra-oral devices can also be used

Central Sleep Apnoea

This is a disorder where patients stop breathing for 10–30 seconds in cycles during sleep leading to reduced oxygen saturations. This results in a build-up of carbon dioxide and subsequent arousal to regain breath, restoring oxygen levels.

It is due to instability in chemoreceptors that monitors CO2 to stimulate breathing.

It is associated with drugs (opioids), altitude and the Arnold-Chiari malformation.

Causes

Drugs (opioids), high altitude,

CPAP (after obstructive sleep apnoea)

Arnold-Chiari Malformation

Symptoms

Observed patterns of stopping breathing and abrupt awakening

Daytime lethargy and sleeping

Morning headache and snoring

Can exacerbate underlying cardiovascular disease (angina)

Key tests

Polysomnography

Management

Address the underlying cause, CPAP/BiPAP can be used