Lower respiratory tract disease - OBSTRUCTIVE SLEEP APNOEA Flashcards
what is sleep apnoea?
= intermittent upper airway collapse in sleep
- characterised by pauses in breathing or periods of shallow breathing during sleep.
- each pause can last for a few seconds to a few minutes
- usually follows LOUD SNORING
who is at the biggest risk of being affected by sleep apnoea?
who else can get it?
- overweight, middle aged men
- but children can get it, especially those with enlarged tonsils
- post-operative period after anaesthesia
what are the symptoms of sleep apnoea?
- loud snoring
- daytime sleepiness
- un-refreshed sleep
- restless sleep
- morning headache
- nocturnal choking
- reduced libido (sexual desire)
- morning drunkenness
- ankle swelling
describe the state of the muscles during sleep apnoea?
- reduced activity of the respiratory muscles
- diaphragm is virtually the only active muscle
describe what happens to the airway at the back of the throat?
- the airway at the back of the throat is SUCKED CLOSED when breathing in during sleep
why does this not occur when your awake but it occurs when your asleep?
When awake;
- tendency is overcome by action of opening muscles of upper airway, the genioglossus and palatal muscles
When asleep;
- these become hypnotic during sleep
what does partial narrowing of the airway result in?
results in SNORING
what does complete narrowing result in?
results in APNOEA
what does apnoea result in?
- results in hypoxia
- increasing respiratory efforts until the patient overcomes the resistance
what wakes the patient from sleep during an apnoea?
- the central hypoxic stimulation and the effort to overcome obstruction wakes the patient from sleep
how is it diagnosed?
- relatives/partners provide a good history about the SNORE-SILENCE-SNORE cycle
- Epworth sleepiness scale distinguishes between simple snoring and obstructive sleep apnoea
- overnight pulse oximetry performed at home
when can you clinically diagnose somebody with obstructive sleep apnoea?
if there are more than 10-15 apnoea in any 1 hour of sleep
how can you manage obstructive sleep apnoea?
1) nasal continuous positive airway pressure (CPAP)
- delivered by a mask during sleep
2) modafinil
3) mandibular advancement device
4) surgery
how does nasal continuous positive airway pressure work?
- it raises the pressure in the pharynx by about 1kPa
- this keeps the walls apart
benefits of nasal CPAP
- improves quality of life
- improves daytime alertness
- improves symptoms
