Sleep apnoea and neuromuscular respiratory disorders Flashcards
What is obstructive sleep apnoea?
Recurrent episodes of upper airway obstruction leading to apnoea (suspensions of breathing for >10secs) during sleep
What are some symptoms of sleep apnoea?
Daytime tiredness due to poor rest
Heavy snoring
Poor daytime concentration
Wake frequently in the night
In what groups is obstructive sleep apnoea commonly seen?
Overweight individuals, mostly men
Young children with enlarged tonsils
What increases the risk of obstructive sleep apnoea?
Obesity Alcohol Hypothyroidism Acromegaly COPD
Why does sleep apnoea happen at night and not during the day?
Throat muscles become hypotonic and are then more likely to fall and be sucked close
What is the prevalence of OSAS?
2% of men and 1% of women
How do we diagnose sleep apnoea?
Clinical history and exam
Epworth questionnaire
Overnight sleep studies
What is the Epworth questionnaire?
Qs on when people feel sleepy
Describe some overnight sleep study tests
Pulse oximetry overnight - O2 sats
Polysomnography - brain waves, O2, HR, RR, eye movements, leg movements, ECG
How do classify the severity of OSAS, depending on the number of desaturations during the night (apnoea/hypopnea index):
0-5 = normal 5-15 = mild 15-30 = moderate >30 = severe
What is hypopnea?
Partial apnoea event, airflow to lung reduced for 10 secs
How can you treat sleep apnoea?
Continous positive airways pressure (CPAP)
Mandibular repositioning splint
What advice should you give to those diagnosed with sleep apnoea?
Lose weight
Reduce alcohol intake
Stop or restrict driving and tell DVLA
What is narcolepsy?
Long term neurological disorder that involves decreased ability to regulate sleep-wake cycles. Leads to:
- excessive daytime sleepiness
- cataplexy
- hypnogogic hallucinations
- sleep paralysis
- can be brought on by strong emotions
What causes narcolepsy?
Not well known, but a familial link is seen in 10% cases (HLA DRB11501 and DBQ10602)
How do you treat narcolepsy?
Modafinil - eugeroic, enhance waking
Clomipramine - cataplexy, TCA
or
Sodium oxybate - if they cant take TCAs
What is a complication of sleep apnoea?
Chronic ventilatory failure
Elevated PCO2 and decreased PO2
Normal acid due to build up of bicarbonate
What can cause chronic ventilatory failure?
COPD Bronchiectasis OSAS Chest wall deformities e.g kyphoscoliosis Motor neurone disease Muscular dystrophy Obesity hypoventilation syndrome
What are the symptoms of chronic ventilatory failure?
Breathlessness Orthopnoea Ankle swelling (hypoxic cor pulmonale) Morning headache Recurrent chest pain Disturbed sleep
What are some clinical signs of chronic ventilatory failure?
Paradoxical abdominal wall movement in neuromuscular disease Ankle oedema (hypoxic cor pulmonale)
What investigations are used for chronic ventilatory failure?
Lying and standing vital capacity Stiff nasal inspiratory pressure Early morning arterial blood gases (ABG) Overnight oximetry Transcutaneous CO2 monitoring Screening of diaphragm
How do you treat chronic ventilatory failure?
Domicillary non-invasive ventilation
Tracheotimised intermittent positive pressure ventilation
Describe REM sleep
rapid eye movement phase
paralysis of skeletal muscle, dreaming