Lecture 16 - Sleep Apnea Flashcards
What is Sleep Apnea?
Sleep apnea is when people stop breathing during sleep.
It is often caused by the airway collapsing during sleep.
If people have 5 or more episodes of apnea or hyponea (partial decrease in airflow that causes them to wake) per hour then they are considered to have sleep apnea.
Those with severe sleep apnea can have over 100 episodes of apnea/hypopnea within an hour.
What is the difference between Obstructive and Central Sleep Apnea?
Obstructive sleep apnea involves respiratory efforts, but no successful breathing.
Central sleep apnea involves no breathing and no efforts to breath.
What is CONGENITAL CENTRAL HYPOVENTILATION SYNDROME?
This is a genetic disorder that impacts the retrotrapezoid nucleus and reduces our ability to respond to CO2 levels. This is a condition where the difficulty in breathing would be characterised as central sleep apnea.
Central sleep apnea is common in those who use opioids. Why?
Opioids decrease function of the chemosensors, reducing information sent to the brain about levels of CO2 and CO2.
Opioids also inhibit the neurons in the pre-boetzinger neurons, preventing the regulation of the rhythm of breathing.
Are opioids respiratory depressants?
Yes.
This is why some people die from overdose of opioids. They just stop breathing.
What is more common obstructive sleep apnea or central sleep apnea?
Obstructive sleep apnea.
1% of people have central sleep apnea.
10% of women and 20% of men have obstructive sleep apnea.
What is obstructive sleep apnea?
The cessation of breathing during sleep caused by a collapse of the upper airway (the soft pallet) onto the back of the throat, preventing air from entering the lungs.
The person continues to try and breath. This is a key differentiator to central sleep apnea.
What happens to the pattern of sleep phases in those with obstructive sleep apnea?
Due to individuals constantly waking up due to apnea, they cannot go down into deep slow wave sleep (phase 3 sleep). They also do not experience much REM sleep.
What are some theories for why some people develop obstructive sleep apnea?
There seems to some anatomical features that are common in those with OSA, such as small chins and more fat under the chin. When lying down this particular structure makes it more easy for the upper respiratory tract to collapse and prevent the inflow of air.
It is thought that the decrease in muscular control that occurs during sleep takes away any compensatory mechanism of the muscles that keep the airway open during the day and the anatomical structure then causes the collapse of the upper airway.
What are some of the consequences for those with Obstructive Sleep Apnea?
The negative consequences that are experienced by those who have OSA are thought to occur due to the repetitive arousal during sleep leading to lack of sleep and not enough slow wave or REM sleep. Also, the hypoxia (lack of oxygen) resulting from apnea.
When measuring the movement of the tongue muscle during sleep, what can be observed in those with sleep apnea?
The respiratory related movement of the tongue stops.
Is there a correlation between subjective feelings of sleepiness and neurocognitive consequences of sleep deprivation?
No.
We experience sleep deprivation subjectively differently and it is not necessarily indicative of the neurocognitive consequences of sleep deprivation.
What percentage of people with OSA have symptoms of depression?
About 40%
Are those with PTSD more at risk of developing OSA?
Yes. This could be because people with PTSD are more sensitive to events of apnea and hypopnea, due to their states of hyperarousal. This could initiate and perpetuate the cycle of OSA.
