Sleep Apnea, Obstructive

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

Demographics

• 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

Diagnosis

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

Treatment

Medications

• 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

Surgery

• 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 ...