Sleep apnoea and neuromuscular respiratory failure

Question 1

What is obstructive sleep apnoea syndrome?

Answer 1

• Recurrent episodes of upper airway obstruction leading to apnoea during sleep
• Usually associated with heavy snoring
• Daytime sleepiness/ poor concentration

Question 2

Why is obstructive sleep apnoea syndrome (OSAS) important?

Answer 2

• Impaired quality of life
• Increased risk of RTA’s (road traffic accidents)
• Marital dysharmony
• Associated with hypertension, increased risk of stroke and probably increased risk of heart disease.

Question 3

How is OSAS diagnosed?

Answer 3

• Clinical history and examination
• Epworth questionnaire
• Overnight sleep study

Question 4

Techniques used for an overnight sleep study

Answer 4

• Pulse oximetry
• Limited sleep studies
• Full polysomnography

Question 5

OSA severity using AHI scale

Answer 5

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

Question 6

Treatment for Sleep apnoea

Answer 6

• Identidy exacerbating factors e.g. weight reduction, avoid alcohol, diagnose and treat endocrine disorders.
• Continuous positive airways pressure (CPAP)
• Mandibular repositioning splint

Question 7

Should patients with sleep apnoea be driving?

Answer 7

NO they should restrict driving and inform DVLA of their condition.

Question 8

Features of Narcolepsy

Answer 8

• Prevalence 0.05%
• Familial
• Associated with HLA - DRB11501 and HLA DQB1 0602

Question 9

Clinical features of Narcolepsy

Answer 9

• Cataplexy
• Excessive daytime somnolence
• Hypnagogoc hallucinations
• Sleep paralysis

Question 10

Treatments for narcolepsy

Answer 10

• Modafinil
• Clomipramine (for cataplexy)
• Sodium Oxybate (Xyrem)

Question 11

Features of Chronic Ventilatory Failure

Answer 11

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

Question 12

Causes of chronic ventilatory failure

Answer 12

• Airways disease e.g. COPD, bronchiectasis, OSA
• Chest wall abnormalities e.g. kyphoscoliosis
• Respiratory muscle weakness e.g. ALS, muscular dystrophy
• Central hypoventilation e.g. obesity hypoventilation syndrome, central hypoventilation syndrome (Ondine’s curse).

Question 13

Typical symptoms of chronic ventilatory syndrome

Answer 13

• Breathlessness
• Orthopnoea
• Ankle swelling
• Morning headache
• Recurrent chest infections
• Disturbed sleep

Question 14

Investigation techniques foe neuromuscular disease

Answer 14

• Lung function e.g. lying and standing VC, Mouth pressure/ SNIP
• Assessment of Hypoventilation e.g. early morning ABG, overnight oximetry, transcutaneous CO2 monitoring.
• Fluoroscopic screening of diaphragms

Question 15

Treatments for neuromuscular disease

Answer 15

• Domicillary non invasive ventilation (NIV)
• Oxygen therapy
• (t-IPPV)