Sleep Apnea

Basics

Description

  • Disorder characterized by cessation of breathing during sleep:
    • Defined as apneic episodes >10 s with brief EEG arousals or >3% oxygenation desaturation
  • Risk factors:
    • Obesity (strongest risk factor)
    • Male
    • >40 yr of age
    • Upper airway anomalies
    • Myxedema (hypothyroidism)
    • Alcohol/sedative abuse
    • Smoking
  • Associated illness:
    • Various dysrhythmias, particularly atrial fibrillation and bradyarrhythmia
    • Right and left heart failure
    • MI
    • Stroke
    • Motor vehicle accidents
    • Hypertension poorly controlled by medical therapies

Epidemiology

  • Affects about 15% of males and 5% of females
  • Prevalence has increased due to higher rates of obesity
  • 80% of moderate or severe cases undiagnosed in middle-aged adults

Etiology

3 classifications of sleep apnea:
  • Obstructive (84%) is due to upper airway closure despite intact respiratory drive:
    • Also known as Pickwickian syndrome
    • Pharyngeal airway is narrowed
  • Central (0.4%) is due to lack of respiratory effort despite patent upper airway
  • Complex (15%) is due to a combination of obstructive and central sleep apnea

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