Sleep apneoea and neuromuscular resp failure

Question 1

Define obstructive sleep apnoea

Answer 1

Recurrent episodes of upper airway obstruction leading to apnoea during sleep

Question 2

Describe some symptoms of obstructive sleep apnoea

Answer 2

Usually associated with heavy snoring
Typically unrefreshing sleep
Daytime somnolence /sleepiness
Poor daytime concentration

Question 3

Which three pathophysiology factors result in closure of upper airway?

Answer 3

Muscle relaxation and narrow pharynx and obesity

Question 4

Describe the consequences of pathophysiology that cause apneoa

Answer 4

poor concentration and daytime hypersomnolence

Question 5

Which 3 conditions is OSAS a risk factor for?

Answer 5

Hypertension, stroke and heart disease

Question 6

How is OSAS diagnosed?

Answer 6

Clinical history and examination
Epworth Questionnaire
Overnight sleep study
pulse oximetry
limited sleep studies
full polysomnography

Question 7

When would polysomnography be used?

Answer 7

Used when considering other rare sleeping disorders

Considers oronasa airflow, body position, ECG, oximetry

Question 8

What is the OSA severity?

Answer 8

Based on events per hour

Desaturation rate / AHI:-

0-5 Normal
5-15 Mild
15-30 Moderate
>30 Severe

Question 9

Describe some exacerbating factors that can be reduced in terms of treatment for OSA

Answer 9

weight reduction

avoidance of alcohol

diagnose and treat
endocrine disorders e.g. hypothyroidism, acromegaly

Question 10

Describe the main treatment offered for those with OSA?

Answer 10

Continuous positive airways pressure (CPAP)

Alternative can be mandibular re positioning splint

Question 11

Which accident is most common for those with OSA?

Answer 11

Driving

Inform DVLA

Question 12

What is the prevalence of nacrolepsy?

Answer 12

0.05%

Question 13

What genes is nacrolepsy associated with?

Answer 13

Associated with HLA - DRB11501 and HLA DQB1 0602
(haplotypes)

Familal

Question 14

Describe the clinical features of nacrolepsy?

Answer 14

Cataplexy
Excessive daytime somnolence
Hypnagogic / hynopompic hallucinations
Sleep paralysis

Question 15

Describe investigation methods of narcolepsy

Answer 15

PSG
MSLT (>1 SOREM and mean sleep latency <8 min).
Low CSF orexin

Question 16

Describe the 4 treatments for narcolepsy

Answer 16

Modafinil
Dexamphetamine
Venlafaxine (for cataplexy)
Sodium Oxybate (Xyrem) - second line to treat sleepiness and cataplexy

Question 17

Define chronic ventilatory failure

Answer 17

Elevated pCO2 (> 6.0 kPA)
pO2 < 8 kPA
Normal blood pH
Elevated bicarbonate (HCO3-)

Question 18

What are the aetiology of chronic ventilatory failure?

Answer 18

Airways disease

• COPD
• bronchiectasis

Chest wall abnormalities

-kyphoscoliosis

Respiratory muscle
weakness

• motor neurone disease (ALS)
• muscular dystrophy
• glycogen storage disease (Pompe’s disease)

Central hypoventilation

• obesity hypoventilation syndrome
• congenital central hypoventilation syndrome (Ondine’s curse)

Question 19

List the typical symptoms of CVF

Answer 19

Breathlessness
Orthopnoea
Ankle swelling
Morning headache
Recurrent chest infections
Disturbed sleep

Question 20

What are things to look out for during examination?

Answer 20

Particularly look for paradoxical abdominal wall motion in suspected neuromuscular disease
Ankle oedema (hypoxic cor pulmonale)

Question 21

What is the 3 investigation techniques for CVF?

Answer 21

Lung function

• Lying and standing VC
• Mouth pressures / SNIP

Assessment of Hypoventilation

• Early morning ABG
• Overnight oximetry
• transcutaneous CO2 monitoring

(Fluoroscopic screening of diaphragms)

Question 22

Describe 2 factors which are expected to be found in pulmonary function test for Chronic ventilation failure

Answer 22

High FEV/FVC ration

Drop in supine FVC

Question 23

Describe treatment for Chronic ventilation failure

Answer 23

Domicillary Non Invasive Ventilation (NIV)
Oxygen therapy
(t-IPPV)