CPRS Case 2: OSA

Question 1

***Gross anatomy of upper airway in relation to snoring and obstructive sleep apnea

Answer 1

Causes of snoring and OSA:
- flow of air through mouth and nose is obstructed
—> soft palate (nasopharynx)
—> tongue (oropharynx)
—> airway

1. Nasal airway:
   - allergy
   - sinus infection
   - deformities
2. Poor muscle tone in throat and tongue
   - aging
   - deep sleep
   - alcohol consumption
   - sleeping pills
3. Bulky throat tissue:
   - overweight
   - large tonsils / adenoids
4. Long soft palate / uvula

Question 2

***Major physiological disturbances during episodes of obstructive sleep apnea and clinical features

Answer 2

1. Reduction in oxygen saturation —> ↑ HR,↑ BP
2. Partial airway obstruction —> vibration of tissues —> snoring
3. Interrupted sleep —> arousal —> daytime sleepiness, chin movement, leg movement
4. Sympathetic activation related to arousal —> vasoconstriction —> systemic hypertension
5. Repeated hypoxic episodes —> Erythropoietin production, Pulmonary vasoconstriction —> Polycythaemia, Pulmonary hypertension, Right heart failure

Question 3

Sleep pattern in healthy adults

Answer 3

Sleep cycle:
5 stages: 1, 2, 3, 4 and REM sleep
- progress cyclically from 1 through REM
- one complete cycle ~90-110 minutes
- 1st cycle: short REM and long deep sleep
- later: REM period length and deep sleep shorten

Stage 1: Light sleep: eyes move slowly and muscle activity slow

Stage 2: HR and body temp decreases

Stage 3/4: Deep sleep: no eye movement/ muscle activity (bedwetting, sleepwalking, night terror)

REM: 90mins after asleep —> HR and breathing increases —> most dreams occurs
3-5 intervals of REM sleep each night

Question 4

Difference in sleep pattern in infants and adults

Answer 4

Infants: 50% REM
Adults: 50% stage 2, 20% REM

Question 5

Control and pattern of breathing during wake and sleep cycle

Answer 5

See lecture

Question 6

Major causes of excessive daytime sleepiness

Answer 6

Primary hypersomnia of central origin (less common)

• Narcolepsy
• idiopathic

Secondary hypersomnia
- Sleep disorder
—> Obstructive sleep apnea
—> Behavioural sleep deprivation (most common)
—> Shift in circadian rhythm
- Medical / psychiatric condition
—> medication effect
—> depression

Question 7

Identify causes of hypertension

Answer 7

1. Essential hypertension (idiopathic)
2. Secondary hypertension
   —> renal (acute glomerulonephritis)
   —> endocrine (phaechromocytoma)
   —> cardiovascular (rigidity of aorta, coarctation of aorta)
   —> neurologic (sleep apnea, acute stress)

Question 8

Possible differences in perception of symptoms from patient’s, peer’s and physician’s perspective

Answer 8

1. Mood
2. Cognition
3. Social environment

See lecture

Question 9

Impact of lifestyle on health

Answer 9

1. Food
—> fruits and vegetables
—> salt and lipid content
2. Exercise
3. Alcohol
4. Smoking

Question 10

Impact OSA can have on activities of daily living

Answer 10

1. Tiredness

2. Drowsiness e.g. during driving

Question 11

Role of public education in recognition of symptoms and promotion of health

Answer 11

• Improve **illness cognition and **symptom perception

- Prevent diseases through ***habitual change and routine checkup

Question 12

Implications of sleepiness on driving

Answer 12

• Danger to driver
• Danger to other drivers
• Danger to pedestrians

Question 13

How to diagnose OSA

Answer 13

Polysomnography