sleep apnoea and narcolepsy

Question 1

what is obstructive sleep apnoea

Answer 1

1. recurrent episodes of upper airway obstruction leading to cessation of breathing during sleep
2. associated with heavy snoring
3. typically unrefreshing sleep
4. leads to daytime sleeping and poor concentration

Question 2

what causes sleep apnoea

Answer 2

muscle relaxation, narrow pharynx and obesity lead to closure of upper airways which leads to snoring and oxygen desaturation.
repeated close of upper airway leads to apneas and hyponeoas which leads to microarousals

Question 3

what are microarousals

Answer 3

moving from light to deep sleep so body isn’t fully rested and leads to daytime sleepiness

Question 4

difference between apnoea and hyponoeas

Answer 4

apnoea when is occurs for more than 10 secs
hyponoeas- less than 10 secs

Question 5

how does OSAS effect everyday life

Answer 5

impaired quality of life, martial disharmony, increased risk of road traffic accidents.

Question 6

how is OSAS diagnosed

Answer 6

clinical history, epworth questionnaire, overnight sleep study

Question 7

how do you treat OSAS

Answer 7

identify exacberating factors- weight reduction, avoidance of alcohol, treat endocrine disease
CPAP, mandibular splint

Question 8

what is CPAP

Answer 8

continuous positive airways pressure- blowing air through tubing to create positive pressure within throat

Question 9

what causes narcolepsy

Answer 9

genetics, HLA genes, low prevalence and often younger age than sleep apnoea

Question 10

clinical features of narcolepsy

Answer 10

cataplexy- sudden collapse during the day due to muscle weakness but are aware of what’s around them
excessive daytime somnolence, hallucinations, sleep paralysis- unable to move

Question 11

investigations of narcolepsy

Answer 11

PSG, MSLT- less than 6 minutes is abnormal
lumbar puncture and measure content of orexin
track REM and if this begins too early its a sign of narcolepsy

Question 12

medicine for narcolepsy

Answer 12

modafinil, dexamphetamine, venlafaxine, sodium oxybate

Question 13

signs of chronic ventilatory failure

Answer 13

elevated partial pressure of carbon dioxide, low partial pressure of oxygen, normal pH, elevated bicarbonate

Question 14

typical symptoms of chronic ventilatory failure

Answer 14

breathlessness, orthopnoea (breathless lying flat), ankle swelling, morning headache, recurrent chest infections, disturbed sleep

Question 15

treatment of chronic ventilatory failure

Answer 15

non invasion ventilation, oxygen therapy,

Question 16

investigations for chronic ventilatory failure

Answer 16

lung function- VC, mouth pressure and SNIP(sniff in and out with resistance)
assessment of hypoventilation- early morning ABG, overnight oximetry

Question 17

examination findings for chronic ventilatory failure

Answer 17

reflects underlying disease, look for paradoxical abnormal wall motion- weakness of diaphragm

Question 18

what causes chronic ventilatory failure

Answer 18

airways disease- COPD, bronchiectasis
chest wall abnormalities
muscle weakness
central hypoventilation