Obstructive sleep apnea (OSA) is the most common sleep-disordered breathing condition, with prevalence of 13% in men and 6% in women, rising to 30-50% in obese populations. Pathophysiology involves repetitive collapse of the pharyngeal airway during sleep at one or more levels (nasal, velopharyngeal/retropalatal, oropharyngeal/retroglossal, hypopharyngeal/epiglottic). Anatomical contributors include retrognathia, macroglossia, tonsillar hypertrophy, long soft palate, and adenoidal hypertrophy in children. Functional contributors include obesity (fat infiltration of pharyngeal walls), reduced upper airway muscle tone during REM sleep, and craniofacial abnormalities.
Diagnosis requires polysomnography (PSG, gold standard) or home sleep apnea testing (HSAT) for moderate-high pretest probability without significant comorbidity. Apnea-hypopnea index (AHI) classifies severity: mild 5-15/h, moderate 15-30/h, severe >30/h. Apnea is cessation of airflow ≥10 seconds; hypopnea is ≥30% reduction in airflow with ≥3% desaturation or arousal. Clinical evaluation includes Epworth Sleepiness Scale (ESS), STOP-BANG questionnaire, Mallampati class, neck circumference >40 cm, BMI, and ENT examination including nasal endoscopy and Friedman tongue position. Drug-induced sleep endoscopy (DISE) identifies anatomical sites of collapse for surgical planning (VOTE: velum, oropharynx, tongue base, epiglottis).
Treatment is multilevel and individualized. First-line therapy includes weight loss (10% reduction can reduce AHI by 30%), positional therapy for supine-dependent OSA, alcohol/sedative avoidance, and CPAP/BiPAP/APAP (gold standard for moderate-severe OSA, 90%+ efficacy with adherence). Mandibular advancement devices (MADs) are alternative for mild-moderate OSA or CPAP intolerance. ENT surgical options include septoplasty, turbinate reduction, and adenoidectomy (nasal level), uvulopalatopharyngoplasty (UPPP), expansion sphincter pharyngoplasty, palatal implants (palatal level), tongue base radiofrequency, transoral robotic surgery (TORS) tongue base resection, midline glossectomy, and genioglossus advancement (tongue base level). Hypoglossal nerve stimulation (Inspire) is FDA-approved for AHI 15-65/h, BMI <32, with non-circumferential collapse on DISE. Maxillomandibular advancement (MMA) achieves highest cure rates (85-95%) for severe OSA. Pediatric OSA: adenotonsillectomy is first-line.