Obstructive Sleep Apnoea

Question 1

What are the risk factors for obstructive sleep apnoea?

Answer 1

Obesity
Male sex
Post-menopausal
FHx OSA
Large neck circumference
Increased volume of soft tissues
Maxillomandibular abnormalities
Black, hispanic or asian
Chronic snoring
Smoking
PCOS
Hypothyroidism
Increasing age

Question 2

What are the symptoms / signs of obstructive sleep apnoea?

Answer 2

Excessive daytime somnolence
Fatigue
Nasal obstruction
Waking with headache

During sleep:
Snoring
Episodic gasping
Restlness
Sleep
Nocturnal heartburn

More common in women:
Insomnia
Nightmares
Depression
Palpitations

Question 3

What tests are involved in polysomnography for obstructive sleep apnoea?

Answer 3

EEG
Electro-oculographic monitoring
EMG of limbs
Pulse oximetry
ECG
Capnography

Question 4

What results of polysomnography are diagnostic of obstructive sleep apnoea?

Answer 4

Apnoea-Hypopnoea Index determined by:

Apnoea episodes - nasal pressure decreased by at least 90% for at least 10 seconds

Hypopnoea episodes - nasal pressure decreased by at least 30% for at least 10 seconds associated with a drop in saturation of at least 3% or with arousal

If greater than 15 episodes per hour then OSA is diagnosed

Question 5

How is obstructive sleep apnoea managed?

Answer 5

Lifestyle - weight loss, sleep hygiene education
Adjunct - glycemic control, antihypertensives
Symptomatic relief for somnolence - modafanil
Treatment - CPAP first line, mandibular repositioning devices 2nd line, upper airway surgery in some patients

Question 6

What are the potential complications of obstructive sleep apnoea?

Answer 6

• Impaired glucose metabolism
• Cardiovascular disease
  
  • Hypertension
  • Dysrhythmias
  • MI
  • Heart failure
• Depression
• Motor vehicle accidents
• Cognitive dysfunction
• Increased mortality