Sleep Disorders Flashcards
What is the function of hypocretin?
Controls junction between sleep and wake and non-REM and REM sleep
When do you have most of your REM sleep?
Later in the sleep
What proportion of sleep is REM in adults?
15%
What is the Epworth sleepiness scale?
Subjective measure of a patient’s propensity to sleep
How does sleepiness and tiredness/lethargy differ?
Sleepiness is the ability to fall asleep very easily cf. general fatigue
What is the most common cause of daytime sleepiness?
Lifestyle - not enough sleep
What are some DDx for daytime sleepiness?
Lifestyle
Drugs/Alcohol
Sleep breathing disorder
Restless leg syndrome
Insomnia
Narcolepsy
What is an elevated Epworth sleepiness scale source? What is the most common cause?
>10
Depression
What is the major control of breathing during sleep?
Chemical control
What are the causes of central sleep apnoea?
Cardiac failure (Cheynes Stokes respiration)
High altitude
CNS disorder
Idiopathic
What is the prevalence of OSA in males and females respectively?
24% of males
8% of females
What are the cardinal symptoms of OSA?
Heavy snoring
Daytime somnolence
Witnessed apnoea
Unrefreshed sleep
Nocturia
What are some consequences of OSA?
Neuro
- Excessive sleepiness
- Psychologic problems
- Stroke
- Dementia
- ADHD
Cardio-Respiratory
- HTN
- Cor pulmonale
- MI
- Arrhythmias/sudden death
- Polycythaemia
What are some risk factors for OSA?
Age
Male
Obesity
Alcohol/Sedatives
Upper airway morphology
What is a significant desaturation during an apnoea?
>4%
How is OSA diagnosed?
Number of events per hour (apnoea hypopnoea index)
5-15: mild
15-30: moderate
>30: severe
What is the definition of an apnoea?
Complete cessation of airflow for 10s or longer
What is an hypopnoea?
30% or more reduction in airflow associated with >3% O2 desaturation or an alpha wave arousal from sleep
How do you assess whether some with diagnosed OSA needs treatment?
Change of long term adverse complications
Clinical picture
Social factors
When is surgery used in OSA?
Children mainly
Rarely adults
What are some conservative management options for OSA?
Weight loss
Avoid alcohol
Body position
Relieve nasal congestion
How does CPAP work?
Continuous positive pressure to open up airways
What is the most common second line therapy for OSA?
Mandibular advancement splint
Why does Cheynes stokes breathing develop in cardiac failure?
It’s more efficient
