Sleep Apnea and Neuromuscular respiratory disorders

Question 1

What is obstructive sleep apnea syndrome?

Answer 1

• recurrent episodes of upper airway obstruction, leading to apnoea during sleep

Question 2

what are features of sleep apnea?

Answer 2

• Poor daytime concentration
• Heavy snoring
• daytime sleepiness
• Unrefreshing sleep

Question 3

Describe the pathophysiology of sleep apnea

Answer 3

• muscle relaxation, narrow pharynx, obesity causing the repeated closure of upper airway
• this causes snoring, oxygen desaturation and apneas/hypopnoeas

Question 4

why is sleep apnea important?

Answer 4

• impaired quality of life and increased risk of stroke, associated with CVDs and hypertension

Question 5

How do you diagnose obstructive Sleep Apnoea Syndrome?

Answer 5

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

Question 6

What does overnight sleep study include?

Answer 6

• overnight oximetry
• full polysomnography
• limited sleep studies

Question 7

Outline the scale for OSA Severity and desaturation rate/AHI.

Answer 7

0-5 Normal

5-15 Mild

15-30 Moderate

> 30 Severe

Question 8

How do you treat obstructive sleep apnoea syndrome?

Answer 8

1. Identify factors which make it worse i.e. obesity, alcohol, diagnose and treat endocrine disorders e.g. hypothyroidism and acromegaly
2. Continous positive airways pressure (CPAP)
3. Mandibular repositioning splint

Question 9

What should you warn patients with OSAS and excessive daytime somnolence?

Answer 9

• Not to drive and inform the DVLA of their condition. only once they are treated can they drive.

Question 10

What are differential to sleep apnoea?

Answer 10

Narcolepsy- rare, the brain is unable to regulate sleep-wake cycle

Question 11

What are clinical features of narcolepsy?

Answer 11

• Sleep paralysis
• Cataplexy (temporary loss of muscle control)
• Hypnagogic/ hypnopompic hallucinations
• Excessive daytime somnolence

Question 12

How do you diagnose Narcolepsy?

Answer 12

• Polysomnography
• Low CSF Orexin
• Mean Sleep Latency Test (>1 SOREM and MSLT <8min)

Question 13

How do you treat narcolepsy?

Answer 13

M odafinil
D examphetamine
V enlafaxine (for cataplexy)
S odium oxybate (Xyrem)

Question 14

What are signs of chronic ventilatory failure?

Answer 14

PaCo2 > 6kPa
PaO2< 8kPa
Elevated bicarbonate (HCO3-)
Normal blood pH

Question 15

How do you investigate neuromuscular diseases?

Answer 15

• Lung function tests
  Lying and standing vital capacity, mouth pressures
• Hypoventilation assessment
  Early morning ABG
  Overnight oximetry
  transcutaneous CO2 monitoring

Question 16

How do you treat neuromuscular respiratory disease?

Answer 16

• non invasive ventilation and oxygen therapy