Obstructive Sleep Apnea (OSA)

Pulmonology / Sleep Medicine

Overview

Definition

A sleep-related breathing disorder characterized by recurrent episodes of complete or partial upper airway obstruction during sleep, resulting in hypoxemia and sleep fragmentation.

Epidemiology

Very common, affecting up to 20% of adults. Strongly associated with obesity.

Etiology & Risk Factors

  • Anatomical narrowing of the upper airway (obesity, large tonsils/adenoids in children, macroglossia, retrognathia)
  • Decreased upper airway dilator muscle tone during sleep

Clinical Symptoms

  • Loud snoring
  • Witnessed apneic episodes (gasping/choking during sleep)
  • Excessive daytime sleepiness
  • Morning headaches
  • Unrefreshing sleep

Clinical Approach

Diagnosis

  • Polysomnography (Sleep Study - Gold Standard): Apnea-Hypopnea Index (AHI) ≥ 5 events/hour with symptoms, or ≥ 15 events/hour regardless of symptoms
  • Home Sleep Apnea Testing (HSAT) is acceptable for uncomplicated patients with high pre-test probability

Management

  • Continuous Positive Airway Pressure (CPAP) - first-line therapy
  • Weight loss (strongly recommended for all obese patients)
  • Avoid alcohol and sedatives before bed
  • Oral appliances (mandibular advancement devices) for mild-to-moderate OSA
  • Surgical options (UPPP, Maxillomandibular advancement) for refractory cases

Complications

  • Resistant Hypertension
  • Atrial Fibrillation
  • Pulmonary Hypertension / Cor Pulmonale
  • Increased risk of Stroke and MI
  • Motor vehicle accidents (due to daytime somnolence)