1. Definition
1.1. Obstructive sleep apnea (OSA) is a disorder that is characterized by obstructive apneas and hypopneas caused by repetitive collapse of the upper airway during sleep.
1.2. CHALLENGE
1.2.1. Selection
1.2.1.1. The challenge is to select the patients who are most likely to have OSA for further diagnostic evaluation
1.3. Types
1.3.1. Central
1.3.1.1. airflow obstruction + abnormal respiratory effort
1.3.2. obstructive: airflow obstruction + normal respiratory effort
1.3.2.1. more common
1.3.3. Combined
2. Epidemiology
2.1. It is estimated that 26 percent of adults are at high risk
2.2. Five hundred and seventy-eight middle-aged Saudi males with a mean age of 45.02
2.2.1. 33.3% were considered as high risk patients for OSA
2.2.2. Snoring??
2.2.3. In primary care setting, one in 3 middle-aged Saudi males is at risk for OSA.
2.2.4. USA?
2.3. 20% if AHI > 5 times/hour
2.3.1. The prevalence of OSA in the general population is approximately 20 percent if defined as an apnea hypopnea index (AHI) greater than five events per hour (the AHI is the number of apneas and hypopneas per hour of sleep)
2.4. Age – The prevalence of OSA increases from 18 to 45 years of age, with a plateau occurring at 55 to 65 years of age
2.5. Ethnicity and race – OSA is more prevalent in African Americans who are younger than 35 years old
2.5.1. USA and Asia, where is more common?
2.6. Gender – Three to 4 percent of women and 6 to 9 percent of men have OSA
2.6.1. No much changes after 6th decade of age
3. Presentation
3.1. Daytime symptoms
3.1.1. Excessive sleepyness
3.1.2. Fatigue
3.1.3. Drawsiness
3.1.4. Forgetfullness
3.1.5. Morning Headache
3.1.6. Personality Changes
3.2. Night symptoms
3.2.1. wakening during the night with choking or gasping
3.2.2. Nocturia
3.2.3. Restless sleep
3.2.4. Dry mouth
4. Sources
5. Risk factors
5.1. Old age
5.2. Chemical intake (alcohol)
5.3. Premature muscular tone loss
5.4. Increase soft tissue
5.5. Structural features that narrow the airway
5.6. Men vs Women
5.7. Genetic
5.8. Life style
5.9. Medication
5.10. Retrognathia
5.11. Large tonsils, neck, collar, tongue
5.12. Obesity
6. Pathophysiology
6.1. Physiology
6.1.1. Neural part
6.1.1.1. Brainstem nuclei coordinate (ventilatory control system)
6.1.1.1.1. ventilatory actions of upper airway muscles
6.1.1.1.2. chest wall muscles
6.1.1.1.3. the diaphragm
6.1.1.2. Phasic neural output induces cyclic increases and decreases of ventilatory muscle activation
6.1.1.2.1. series of breaths that comprise the ventilatory rhythm
6.1.2. Anatomical part
6.1.2.1. Upper airway patency is maintained by
6.1.2.1.1. bony and cartilaginous structures surrounding the naso- and oropharynx
6.1.2.1.2. twelve pairs of skeletal muscles
6.2. Pathology
6.2.1. reduced upper airway size
6.2.1.1. diminished neural output to the upper airway muscles during sleep
6.2.1.2. excess surrounding soft tissue or a highly compliant airway
6.2.2. respiratory drive is less than the threshold
6.2.2.1. for inspiratory muscle activation
6.2.2.2. and for maintaining upper airway patency during sleep
6.2.3. apnea progresses and respiratory drive increases until a threshold is passed
6.2.4. Inspiration then occurs
6.2.5. overshoot in ventilation drives down carbon dioxide levels (hyperventilation!)
6.2.6. respiratory drive will fall down due to hyperventilation (over shooting)
6.2.7. Loop again!
6.2.7.1. the next apnea results from overcompensation for the prior apnea