Sleep Apnoea and Narcolepsy Flashcards
What is OSAS?
Recurrent episodes of upper airway obstruction, leading to apnoea during sleep.
What can cause repeated closure of the upper airway?
Muscle relaxation.
A narrow pharynx.
Obesity.
What does repeated closure of the upper airway cause?
Snoring.
Oxygen desaturation.
Apnoeas and hypopneas.
Frequent microarousals - daytime sleepiness and poor concentration.
What is the importance of OSAS?
Impaired QoL.
Marital disharmony.
Increased risk of RTAs.
Associated with hypertension, and increased risk of stroke and heart disease.
How is OSAS diagnosed?
Clinical history and examination.
Epworth Questionnaire (how likely are you to fall asleep in the following situations?).
Overnight sleep study - pulse oximetry, limited sleep studies, full polysomnography.
What is recorded in a full polysomnography?
Thoracoabdominal movement.
Oronasal airflow and body position.
EEG, EOG, EMG, ECG.
What are central apnoeas?
Less common than obstructive apnoeas.
Cessation of breathing due to an absence of a respiratory drive.
How is the severity of OSAS measured?
Desaturation rate, or AHI (the number of apnoeas and hypopnoeas during sleep, divided by the number of hours asleep).
0-5 = normal.
5-15 = mild.
15-30 = moderate.
>30 = severe.
What is the treatment of OSAS?
Exacerbations - weight reduction, avoidance of alcohol, diagnose and treat endocrine disorders.
CPAP - continuous positive airway pressure.
Alternative to CPAP - mandibular repositioning splint.
What is the importance of driving in OSAS?
Patients with sleep apnoea and excessive daytime somnolence are advised not to drive or to restrict driving, and to inform the DVLA of their condition. Once satisfactorily treated, they should be allowed to drive.
What are the risk factors of narcolepsy?
Familial, associated with genetics.
What are the symptoms of narcolepsy?
Cataplexy.
Excessive daytime somnolence.
Hypnagogic hallucinations.
Sleep paralysis.
Sleep begins with REM sleep.
What are the investigations for narcolepsy?
Polysomnography.
MSLT - put the patient in a dark room during the day and advise them to fall asleep. Monitor brain waves via EEG. Abnormal = falling asleep in <6 minutes.
Low CSF orexin.
What is the treatment of narcolepsy?
Modafinil.
Dexamphetamine.
Venlafaxine (for cataplexy).
Sodium Oxybate (Xyrem).
What is OSAS associated with?
Associated with heavy snoring, unrefreshing sleep, daytime sleepiness, and poor daytime concentration.
