Sleep apnoea

Question 1

What is obstructive sleep apnoea syndrome?

Answer 1

• recurrent episodes fo upper airway obstruction leading to apneoa during sleep
• associated with heavy snoring and hypertension

Question 2

OSAS risks

Answer 2

-more likely to get stroke, risk of heart disease

Question 3

Diagnosis of OSAS

Answer 3

• clinical/examination
• epworth questionaire
• overnight sleep study: pulse oximetry, limited sleep studies, full polysomnography

Question 4

Polysomnography

Answer 4

-oronasal airflow
-thoracoabdominal movement
-oximetry
-body position
-EEG
-audiovissuual recording
-EOG
-EMG( perpheral muscle)
ECG

Question 5

OSA severity

Answer 5

Desaturation rate/AHI
0-5 Normal
5-15 Mild
15-30 Moderate
>30 Severe

Question 6

Treatment of OSAS

Answer 6

• identify underlying factors (weight reduction, cutting alcohol, diagnose/treat endocrine disorderes such as hypothyroidism/acromegaly)
• continous positive airways pressure
• mandibular repositioning splint

Question 7

Driving - OSAS/excessive daytime somnolence

Answer 7

-inform DVLA of condition and advise patient not to drive

Question 8

Nacrolepsy

Answer 8

• familial

- associated with HLA - DBRBI* 1501 and HLA DQBI* 0602

Question 9

Clinical features

Answer 9

• cataplexy
• excessive daytime somnolence
• hypnagogic/hynopompic hallucinations
• sleep paralysis

Question 10

Investigation

Answer 10

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

Question 11

Treatment

Answer 11

• Modafinil
• dexamphetamine
• venlafaxine ( for cataplexy)
• sodium oxybate (xyrem)

Question 12

Chronic ventilatory failure

Answer 12

• High PCO2
• Low PO2
• Normal blood pH?
• elevated bicarbonate

Question 13

Causes of chronic ventilatory failure

Answer 13

Airways disease

• COPD
• bronchiectasis

Chest wall abnormalities
-kyphoscoliosis

Respiratory muscle weakness

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

Central hypoventilation

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

Question 14

Symptoms

Answer 14

• SOB
• orhopnoea
• ankle swelling
• morning headache
• disturbed sleep
• recurrent CI

Question 15

Examination findings

Answer 15

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

Question 16

Investigation f neuromuscular disease

Answer 16

Lung function

• lying/standing VC
• mouth pressures/SNIP

Assestment of hypoventilation

• early morning ABG
• overnight oximetry
• transcutaenous CO2 monitoring

Fluroscopic creening of diaphragm

Question 17

Treatment of neuromuscular disease

Answer 17

-domicillary non invasive ventilation
-oxygen therapy
(t-IPPV)