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For further information, see CMDT Part 9-43: Obstructive Sleep Apnea

Key Features

Essentials of Diagnosis

  • Daytime somnolence or fatigue

  • A history of loud snoring with witnessed apneic events

  • Overnight polysomnography demonstrates apneic episodes with hypoxemia

General Considerations

  • Upper airway obstruction results from a loss of pharyngeal muscle tone during sleep

  • Patients with narrowed upper airways are predisposed to the condition

  • Ingestion of alcohol or sedatives before sleep and nasal obstruction from any cause may precipitate or worsen the condition

  • Cigarette smoking and hypothyroidism are risk factors


  • Most patients are obese, middle-aged men

Clinical Findings

Symptoms and Signs

  • Patients complain of daytime somnolence or fatigue, morning sluggishness, or cognitive impairment

  • Recent weight gain, headaches, and erectile dysfunction may be present

  • Bed partners usually report loud cyclical snoring and witnessed apneas with restlessness and thrashing movements during sleep

  • Arterial hypertension is usually present

  • Physical examination may show evidence of pulmonary hypertension with cor pulmonale

  • Oropharyngeal narrowing due to excessive soft tissue may be seen

  • A short, thick neck is common

  • Bradydysrhythmias may occur during sleep

  • Tachydysrhythmias may be seen once airflow is reestablished following an apneic episode

Differential Diagnosis

  • Central sleep apnea

  • Mixed sleep apnea

  • Obesity-hypoventilation syndrome (Pickwickian syndrome)

  • Narcolepsy

  • Alcohol or sedative abuse

  • Depression

  • Hypothyroidism

  • Seizure disorder


Laboratory Tests

  • Erythrocytosis is common

  • Serum thyroid-stimulating hormone (TSH) should be checked

Diagnostic Procedures

  • Overnight polysomnography is essential to make the diagnosis

    • Includes electroencephalography, electro-oculography, electromyography, electrocardiography, pulse oximetry, and measurement of respiratory effort and airflow

    • Reveals apneic episodes lasting as long as 60 seconds

  • Oxygen saturation falls, often to very low levels

  • Bradydysrhythmias such as sinus bradycardia, sinus arrest, or atrioventricular block may occur

  • Tachydysrhythmias, including paroxysmal supraventricular tachycardia, atrial fibrillation, and ventricular tachycardia, may be seen once airflow is reestablished

  • Screening with home studies cannot quantify the stages of sleep, but it can provide a reliable index of respiratory events and desaturations



  • Pitolisant, H3-receptor antagonist/inverse agonist

    • For patients who are unable or unwilling to use CPAP and who may not be surgical candidates

    • Has been shown to improve sleepiness and fatigue


  • Uvulopalatopharyngoplasty, the resection of pharyngeal tissue and removal of a portion of the soft palate and uvula, is helpful in approximately half of selected patients

  • Nasal septoplasty is performed if gross nasal septal deformity is present

  • Tracheostomy is definitive therapy, but is reserved for life-threatening, refractory cases

Therapeutic Procedures

  • Weight loss ...

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