Sleep Apnoea Flashcards
(34 cards)
What is obstructive sleep apnoea?
Recurrence episodes of upper airway obstruction leading to apnoea during sleeping
What are consequences of sleep apnoea?
Heavy snoring Unrefreshing sleep Day time somnolence Compensated resp. acidosis HTN
What are predisposing factors for OSA?
Obesity
Macroglossia: acromegaly, hypothyroidism, amyloidosis
Large tonsils
Marfan’s syndrome
What is the pathophysiology of sleep apnoea?
Muscle relaxation, narrow pharynx, obesity –> repeated closure of upper airway –> oxygen desaturation and snoring, apnoea/hyponeas –> frequent microarousals –> poor concentration and day time somnolence
Why is OSA important?
Reduced QoL Martial dysharmony Increased risk of RTAs Associated with risk of hypertension Increased stroke and CV risk
How to do you assess someone with OSA?
History and exam
Epworth sleepiness scale
Multiple sleep latency test
What is the multiple sleep latency test?
Measures time taken to fall asleep in a dark room using EEG criteria
What diagnostic tests are used to diagnose OSA?
Sleep studies (polysomnography) - ranges from monitoring of pulse oximetry at night to full polysomnography with EEG, respiratory airflow, thoraco-abdominal movement, snoring and pulse oximetry
What score on the Epworth scale is considered excessive sleepiness?
> 11/24
What is the AHI?
Apnoea hypnoea index (number of apnoea/hypnoeas per hour of sleep)
How is the severity of OSA measured?
AHI
What AHI is considered normal?
<5
What AHI is considered mild OSA?
5-15
What AHI is considered moderate OSA?
15-30
What AHI is considered severe OSA?
=>30
What is involved in the management of OSA?
Weight reduction
Avoid alcohol (worsens OSA and snoring)
Diagnose + treat endocrine disorders (e.g. hypothyroidism, acromegaly)
CPAP is first line for mod-severe OSA
Intra-oral devices (e.g. mandibular advancement) can be used in CPAP not tolerated/mild OSA with no daytime sleepiness
How does CPAP help treat OSA?
Keeps airway patent
What patients need to inform the DVLA about their OSA?
Those with OSA what is causing excessive daytime sleepiness
What is nacrolepsy?
Chronic sleep boundary disorder that affects control of sleep and wakefulness with rapid eye movement sleep intrusion into wake state
What is the classic triad of nacrolepsy?
NB this is only seen in 10-15% of cases
- Excessive daytime sleepiness
- Cataplexy
- Sleep paralysis/hypnagogic/hypnopompic hallucinations
What is cataplexy?
Sudden and transient loss of muscular tone caused by strong emotion (e.g. laughter, being frightened)
Can range from knees buckling to collapse
Low levels of what protein is associated with nacrolepsy?
Orexin (hypocretin) a protein which is responsible for controlling appetite and sleep patterns
What HLA allele is associated with nacrolepsy?
HLA-DR2
What is sleep paralysis?
Immobility on arousing from sleep (can be associated with hypnopompic hallucinations)
