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Obstructive sleep apnoea in adults: diagnosis and surgery
The first treatment of obstructive sleep apnoea in adults is CPAP; surgery suits those who cannot adapt to or succeed with CPAP, and is chosen by the site of obstruction (on drug-induced sleep endoscopy — DISE), by anatomy and by BMI — from nasal surgery, through palatal and tonsil surgery and hypoglossal nerve stimulation, to maxillomandibular advancement.
Why it matters in the exam
AASM definitions: apnoea — a fall of 90% or more in airflow for at least 10 seconds; hypopnoea — a fall of 30% or more in airflow for at least 10 seconds, with a fall of 3% or more in oxygen saturation or an arousal. AHI: 5 to 15 — mild; 15 to 30 — moderate; over 30 — severe. A common question: a patient with normal BMI, moderate-to-severe AHI and no abnormal anatomy — the first treatment is CPAP, not surgery. A mandibular advancement device suits mild to moderate disease or CPAP intolerance.
Under AASM 2021, an adult with BMI under 40 who cannot adapt to CPAP should be referred for surgical consultation. DISE describes the site and pattern of collapse by VOTE — velum, oropharynx, tongue base and epiglottis. Large tonsils, a favourable tongue position and low BMI (Friedman stage I) predict good success of UPPP. Nasal surgery does not lower AHI significantly, but improves CPAP adherence. The most important muscle in closing the nasopharynx is levator veli palatini; the only soft palate muscle supplied by nerve V3 is tensor veli palatini.
Hypoglossal nerve stimulation suits, under the 2023 FDA approval, AHI 15 to 100 and BMI up to 40, after CPAP failure, provided there is no complete concentric collapse at the palate on DISE. Maxillomandibular advancement (MMA) is the most effective operation for sleep apnoea, with high success rates. Bariatric surgery suits morbid obesity. Tracheostomy bypasses all obstruction and is reserved for especially severe cases.
Key points
- CPAP first line.
- Hypopnoea: 30% and 3% or arousal.
- DISE guides surgery.
- Hypoglossal stimulation: AHI 15 to 100, BMI up to 40.
- MMA — the most effective operation.
Summary table
| Definition or treatment | Value or indication | Note |
|---|---|---|
| Apnoea | Fall of 90% or more, 10 seconds | AASM |
| Hypopnoea | Fall of 30% or more, 10 seconds, with 3% or arousal | AASM |
| Severity | AHI 5 to 15, 15 to 30, over 30 | Mild, moderate, severe |
| CPAP | First line | At any symptomatic grade |
| Hypoglossal nerve stimulation | AHI 15 to 100, BMI up to 40 | No concentric palatal collapse |
| MMA | Multilevel obstruction, young patient | The most effective operation |
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Sources
- AASM Manual for the Scoring of Sleep and Associated Events, version 3 (2023) — Respiratory events: apnoea and hypopnoea
- AASM Clinical Practice Guideline: Referral of adults with obstructive sleep apnea for surgical consultation, 2021 — Recommendations
- Cummings Otolaryngology: Head and Neck Surgery, 7th edition (2021) — Surgical management of sleep-disordered breathing
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.