SM 185a - Sleep Flashcards
What is sleep good for?
(What is happening in our body when we sleep?)
- Memory consolidation
- Energy conservation
- Brain restoration
- Protective behavioral adaptation
- Immune function
How does the following change during an episode of upper airway obstruction?
Stroke volume
Decreases
Due to pumonary vasoconstriction and septal bowing into the LV
How does the following change during an episode of upper airway obstruction?
Venous return
Increases
Due to negative intra-throacic pressure
The _______ principle and the ________ effect contribute to the physics of OSA
The Bernoulli** principle and the **Venturi effect contribute to the physics of OSA
How does the following change during an episode of upper airway obstruction?
LV afterload
Increases
Due to negative intra-thoracic pressure
What are the symptoms of OSA?
- Unrefreshing sleep
- Daytime sleepiness/fatigue
- AM headache
- Memory and learning impairments
- Hyperactivity (especially in children)
- Insomnia
- Vivid dreams
- Snoring
How does the following change during an episode of upper airway obstruction?
Transmural pressure
Increases
-> Increased LV afterload and venous return
What is the prevalence of OSA?
2-24%, depending on the population
Hormonal systems’ contributions to OSA physiology have been noted in which medical conditions?
(Select all that apply)
- Post-menopausal women
- Polycystic ovary disease
- Hyperthyroid disease
- Addison’s disease (low cortisol)
- Diabetes
- Hyperparathyroidsism
a. Post-menopausal women
b. Polycystic ovary disease
e. Diabetes
Which arrhythmias are more common in patients with OSA?
Atrial fibrillation
Tachy-Brady syndrome
*Note: People with OSA have worse outcomes with cardioversion after atrial fibrillation
How does OSA impact risk of CV events?
OSA = increased risk of CV events
Also, worse outcomes for people with known CAD and OSA
Which of the following patients would be most likely to benefit from CPAP therapy?
- A 42 year-old female with BMI 28 and AHI 7, without significant symptoms
- A 75 yeal-old male with heart failure with a recent, large embolic stroke
- A 56 year-old male with BMI 35 and AHI 66
- A 62 year-old female with amyotrophic lateral sclerosis and significant dyspnea when supine
c. A 56 year-old male with BMI 35 and AHI 66
What are the anatomical risk factors for OSA?
Oropharyngeal crowding that impedes airflow
May be caused by…
- Excessive tissue
- Obesity, tonsillar hypertrophy
- Micrognathia (small chin)
- Macroglossia
- Impaired oropharyngeal muscle tone
List some of the cardiopulmonary effects of OSA
- Upper airway obstruction -> negative intrathoracic pressure
- Increased transmural pressure
- Increased LV afterload
- Increased venous return
- Hypoxia due to obsruction
- Pulmonary vasoconstriction + Septal bowing into the LV
- Decreased LV filling
- Stroke voume
- Pulmonary vasoconstriction + Septal bowing into the LV
How can you tell the difference between obstructive and central apnea?
Why is it important to do so?
No airflow in both central and obstrutive sleep apnea
-
Central: No diaphragmatic excursions
- The patient is not trying to breath
- There is central dysregulation of the breathing pattern
- Treatment: Requires breathing machine that can provide a backup rate
-
Obstructive: Diaphragmatic excursions
- The patient is trying to breathe, but air is not flowing
How do you know if an apea is obstructive?
Active effort but impaired flow
You will see periods of zero airflow with diaphragmatic excursions: The patient is trying to breathe, but air is not flowing
How does the ratio of N3 (deep) sleep to REM sleep change with successive sleep cycles during the night?
The first sleep cycle has very little REM sleep and a lot of N3 (deep) sleep
As the night continues, each successive cycle contains less N3 sleep and more REM sleep
What breathing pattern is this?
What does it indicate?
Cheyne-Stokes breathing
It indicates dysregulation of the body’s normal response to changed PCO2 levels
