Obstructive Sleep Apnoea

Question 1

Define Obstructive sleep apnoea

Answer 1

Upper airway narrowing provoked by sleep causing sufficient sleep fragmentation to result in significant daytime symptoms, usually excessive sleepiness

Question 2

What are some of the risk factors for Obstructive sleep apnoea?

Answer 2

Male
Overweight
Small sized or set back mandible

Question 3

What are the two main causes of excessive narrowing in Obstructive sleep apnoea?

Answer 3

Pharyngeal size already small, undergoes normal amount of narrowing when patient asleep. Becomes too narrow
OR
Excessive narrowing occurring when the patient is asleep

Question 4

What are some of the causes of a small pharyngeal size?

Answer 4

Fatty infiltration of pharyngeal tissue
External pressure from increased neck fat/muscle bulk
Large tonsils
Craniofacial abnormalities
Extrasubmucosal tissue eg myoedema

Question 5

What are some of the cause of excessive narrowing of the airway during sleep?

Answer 5

Obesity
Neuromuscular disease may cause loss of dilator muscle tone eg Stroke, MND
Msucle relaxants eg Sedatives, Alcohol
Increasing age

Question 6

What are some of the symptoms of Obstructive sleep apnoea?

Answer 6

Excessive daytime sleepiness due to repetitive upper airway collapse causing arousal
Nocturia
Nocturnal sweating
Reduce libido
Oesophageal reflux

Question 7

What does the Epworth sleepiness scale measure?

Answer 7

Chances of sleeping in the following situations;
Sitting & Reading
Watching TV
Sitting in a public place
Passenger in a car for an hour
Lying down to rest in the afternoon
Sitting & Talking
Sitting quietly after lunch without alcohol
In a car while stopped in traffic

Question 8

How do you diagnose Obstructive sleep apnoea?

Answer 8

Overnight oximetry
Limited sleep studies - Oximetry, snoring, body movement, HR, oronasal flow, chest/abdominal movements, leg movements
Full polysomnography - limited study plus EEG, EMG

Question 9

How do you manage mild OSA?

Answer 9

Mandibular advancement devices

Pharyngeal surgery as a last resort

Question 10

How do you manage significant OSA?

Answer 10

Nasal CPAP
Consider gastroplasty/bypass
Rarely tracheostomy

Question 11

How do you manage severe OSA with CO2 retention?

Answer 11

NIV prior to CPAP if acidotic. Compensated CO2 may reverse with CPAP alone

Question 12

What is the initial management of OSA?

Answer 12

Weight loss
Sleep lying down
Avoid/reduce evening alcohol intake
Patients need to notify the DVLA