Obstructive Sleep Apnoea

Question 1

What is obstructive sleep apnoea characterised by?

Answer 1

Recurrent episode of partial or complete upper airway obstruction during sleep

Question 2

Episode of OSA lead to what?

Answer 2

Intermittent hypoxia
Hypercapnia
Sleep fragmentation

Question 3

OSA contributes to what?

Answer 3

Various systemic complications:
- cardiovascular disease
- impaired cognitive function

Question 4

Inspiration airflow from the nasal and oral cavities must travel through what before it reaches the trachea and lower respiratory tract?

Answer 4

Nasopharynx
Oropharynx
Laryngopharnyx
Larynx

Question 5

A critical narrowing or obstruction at any of the points in the upper respiratory tract results in what?

Answer 5

Reduced or completely blocked airflow during sleep

Question 6

What factors contribute to airway obstruction?

Answer 6

Nasopharyngeal and oropharyngeal obstructions
Craniofacial abnormalities
Obesity and soft tissue deposition
Sleep-related muscle relaxation

Question 7

Describe nasopharyngeal and oropharyngeal obstructions

Answer 7

Allergic rhinitis or chronic inflammation may lead to mucosal swelling, narrowing the nasopharyngeal airway
Hypertrophic adenoids or enlarged tonsils, often due to infection or chronic inflammation, can contribute to airway obstruction, especially in paediatric and young adult populations

Question 8

Describe craniofacial abnormalities

Answer 8

A retrognathic jaw (severe overbite) can cause posterior displacement of the tongue and soft palate, reducing airway patency
A narrow or high-arched palate may further limit airflow through the upper airway

Question 9

Describe obesity and soft tissue deposition

Answer 9

Excess adipose tissue in the neck and upper airway can contribute to pharyngeal narrowing (especially those with a high BMI)
When lying supine, weight of excess soft tissue exacerbates airway collapse - recurrent obstruction
More common in obese patients

Question 10

Describe sleep-related muscle relaxation

Answer 10

Nocturnal reductions in neuromuscular tone lead to a loss of structural support in the upper airway (especially in the genioglossus and tensor palatini muscles
Fluctuations in hormonal levels during sleep contribute to further airway muscle relaxation, increasing susceptibility to obstruction

Question 11

The fluctuation in which hormone levels can contribute to OSA?

Answer 11

Reduce circulating catecholamines

Question 12

Risk factors of OSA

Answer 12

Obesity
Getting older - it can occur in children
Family history
Smoking
Drinking alcohol
Large tonsils or adenoids
Sleeping on your back
COPD

Question 13

What are the clinical consequences and associated risks of OSA?

Answer 13

Daytime fatigue due to sleep fragmentation
Hypertension and poor cardiovascular outcomes
Difficulty concentrating at work or in school
Low mood or depression
Type 2 diabetes
Metabolic dysfunction-associated steatotic liver disease (MASLD)

Question 14

Describe hypertension and poor cardiovascular outcomes

Answer 14

Many of the risk factors of OSA also contribute to these conditions
Patients with OSA have a heightened sympathetic drive during sleep - BP not dropping overnight.
Increased BP overnight can significantly increase the risk of poor cardiovascular outcomes

Question 15

How does difficulty concentrating at work or school have an impact?

Answer 15

Long term financial impacts
Low academic performance

Question 16

How can it cause low mood or depression?

Answer 16

Due to feeling fatigues everyday alongside the other effects it can have on health

Question 17

How is type 2 diabetes linked to OSA?

Answer 17

Many overlapping risk factors
Studies demonstrate a reduction in insulin sensitivity in patients with OSA

Question 18

How is MASLD linked to OSA?

Answer 18

High levels of visceral fat have been link to OSA and MASLD

Question 19

Symptoms of OSA

Answer 19

Sleep deprivation
Nocturia
Difficulty concentrating
Headaches
Fatigue
Can worsen other problems
- low O2 -> arrhythmia
- increased risk of heart failure, respiratory failure, diabetes, types of cancer

Question 20

Further history taking and investigation is needed in patients with 2 or more of which symptoms?

Answer 20

Snoring
Witnessed apnoeas
Waking still feeling tired
Headaches upon waking
Excessive sleepiness, tiredness and/or fatigue
Nocturia
Choking while asleep
Insomnia
Cognitive dysfunction/memory impairment

Question 21

What is part of the initial assessment of diagnosing OSA?

Answer 21

History taking

Question 22

What does history taking determine?

Answer 22

How likely OSA is
The affect it is having on the patient

Question 23

What tool is used?

Answer 23

The ESS tool

Question 24

What does the ESS tool do?

Answer 24

How much a patient is affected by daytime sleepiness

Question 25

In the ESS tool, what situations are given to a patient for them to rate out of 0-3 their chance of dozing?

Answer 25

Sitting and reading Watching TV Sitting, inactive in a public place As a passenger in a car for an hour without a break Lying down to rest in the afternoon when circumstances permit Sitting and talking to someone Sitting quietly after a lunch without alcohol In a car, while stopped for a few minutes in traffic

Question 26

After using the ESS tool, what is the next step in diagnosis?

Answer 26

Patient is reviewed at a specialist sleep clinic

Question 27

Which patients are prioritised based on their history?

Answer 27

Those with a role as a professional driver - lorry driver, pilot, works heavy machinery Patients advised not to drive while awaiting assessment Have comorbidities like COPD, angina, HF, pulmonary hypertension, resp failure

Question 28

What is an example of a sleep study performed for OSA diagnosis?

Answer 28

Polysomnography

Question 28

What are the different pads used to monitor?

Answer 28

Brain activity Belt monitors breathing Microphone records snoring Muscle movements Pulse-ox

Question 29

Except from polysomnography, what other study is used?

Answer 29

Oxygen desaturation index

Question 30

What is oxygen desaturation index?

Answer 30

Overnight pulse ox is performed Hypoxia - can see how high risk they are for adverse outcomes

Question 31

What does treatment depend on?

Answer 31

Severity Impact on individuals life

Question 32

What is first line treatment for OSA?

Answer 32

Continuous Positive Airway Pressure (CPAP)

Question 33

How does CPAP work?

Answer 33

Provides positive airway pressure Acts to support the upper airways to stay open and prevent collapse during sleep

Question 34

Initially, what is the problem with CPAP?

Answer 34

Can be poorly tolerated but with support and education, many patients are able to tolerate it

Question 35

What does evidence show about the use of CPAP?

Answer 35

Reduces daytime sleepiness Increase QOL May lower BP No confirmed benefit on reducing rates of cardiovascular or stroke

Question 36

When are Intra-oral Mandibular Advancement Devices used?

Answer 36

Mild cases Those unable to tolerate CPAP

Question 37

What are intra-oral mandibular advancement devices?

Answer 37

A dental professional creates plates that support the upper and lower teeth. Worn during sleep to push the mandible and tongue forward to reduce the risk of airway collapse during sleep

Question 38

Intra-oral mandibular advancement devices require patients to have what?

Answer 38

Optimal dental and periodontal health

Question 39

What are the surgical interventions?

Answer 39

Tonsillectomy Oropharyngeal surgery

Question 40

When is tonsillectomy considered?

Answer 40

Those who have large obstructive tonsils and a BMI of less than 35kg/m2

Question 41

When might oropharyngeal surgery be an option?

Answer 41

Those with severe OSA who can't tolerate CPAP or mandibular advancement devises despite medically supervised attempts

Question 42

What lifestyle advice may be suggested to patients with OSA?

Answer 42

Weight management Smoking cessation Alcohol reduction Sleep hygiene Effective management of any comorbidities

Question 43

Why would alcohol reduction be suggested?

Answer 43

Alcohol drank before bedtime can relax throat muscles and worsen apnoea events

Question 44

Describe sleep hygiene

Answer 44

Maintain a regular sleep schedule Create conductive sleep environment