😴 Sleep apnoea comes in two forms:
- Central Sleep Apnoea 🧠 (rare – failure of central respiratory drive)
- Obstructive Sleep Apnoea (OSA) 🚫 (common – pharyngeal airway collapse).
👉 In practice, OSA is the key concern: repeated airway obstruction → oxygen desaturation, micro-arousals, fragmented sleep, and systemic complications.
🔎 Key Clinical Features
- 💤 Excessive daytime sleepiness – main complaint; screen with Epworth Sleepiness Scale.
- 😩 Fatigue & poor concentration – persistent “tired all the time.”
- 😴 Loud snoring & witnessed apnoeas – partners often report pauses in breathing.
- 💧 Nocturia & morning headaches – due to nocturnal hypoxia and arousal.
- ⏰ Non-restorative sleep – unrefreshed despite “7–8 hours of sleep.”
⚙️ Why Does the Airway Collapse?
- 🔄 Reduced pharyngeal tone during sleep → airway collapses.
- 💨 Negative inspiratory pressure further narrows the pharynx.
- ⚖️ Obesity & anatomy: large neck circumference = major risk factor.
- 🚬 Smoking & alcohol relax/irritate airway, worsening obstruction.
- 👀 Partner observations – snoring, choking, or gasping episodes.
- 🚗 Driving risk: OSA → ↑ risk of single-vehicle RTAs (must notify DVLA if symptomatic).
🧪 Investigations
- 🛌 Polysomnography (sleep study): Gold standard (EEG, airflow, O₂ sat, respiratory effort).
- 📊 Apnoea–Hypopnoea Index (AHI): ≥15/hr = clinically significant OSA.
- 📋 Epworth Sleepiness Scale: >10 = abnormal; useful for screening and follow-up.
😴 Obstructive Sleep Apnoea - Diagnostic Criteria
OSA is diagnosed when there are recurrent episodes of upper airway obstruction during sleep, causing hypopnoea/apnoea, intermittent hypoxia, and sleep fragmentation.
📊 Apnoea–Hypopnoea Index (AHI)
|
|
| Severity |
AHI (events/hour) |
Clinical Notes |
| Mild OSA |
5 – 14 |
Daytime sleepiness, often subtle |
| Moderate OSA |
15 – 29 |
Excessive daytime sleepiness, impaired concentration |
| Severe OSA |
≥ 30 |
Marked sleepiness, high CV/metabolic risk |
📖 Diagnostic Criteria (ICSD-3)
- AHI ≥5 events/hour plus symptoms (excessive sleepiness, unrefreshing sleep, fatigue, insomnia, choking/gasping at night, witnessed apnoeas) OR
- AHI ≥15 events/hour, even if asymptomatic.
🔎 Screening Tools
- 🌙 Epworth Sleepiness Scale (ESS): ≥10 suggests excessive daytime sleepiness.
- 🛑 STOP-BANG questionnaire: Snoring, Tiredness, Observed apnoea, high blood Pressure, BMI >35, Age >50, Neck circumference >40 cm, male Gender.
🩺 Investigations
- Polysomnography (gold standard): Sleep study with EEG, oximetry, airflow, chest/abdominal movements.
- Home sleep apnoea testing: Limited but more accessible.
💊 Management
- 💡 Lifestyle: weight loss, reduce alcohol/sedatives, smoking cessation, sleep hygiene.
- 😷 CPAP: first-line in moderate–severe OSA.
- 🦷 Mandibular advancement splints: in mild
⚠️ Complications & Risks
- 🩺 Systemic hypertension – both a cause and consequence.
- ❤️ Cardiovascular disease: ↑ risk of MI, stroke, arrhythmias, sudden death.
- 🚨 Accidents: Somnolence → road traffic accidents (DVLA rules apply).
- 🫁 Pulmonary hypertension & right heart strain in severe untreated OSA.
🩺 Management Strategies
- ⚖️ Lifestyle: Weight loss (most effective), avoid alcohol/sedatives, stop smoking, treat nasal congestion, lateral sleeping position.
- 💨 CPAP (Continuous Positive Airway Pressure): Gold standard for moderate–severe OSA; improves alertness, reduces BP, prevents accidents.
- 🦷 Mandibular advancement devices: For mild OSA or CPAP intolerance.
- 🔪 Surgery: Tonsillectomy, uvulopalatopharyngoplasty (UPPP), or maxillofacial surgery in selected cases.
💡 Teaching Pearls
- 📉 Even modest weight loss can halve OSA severity.
- 📈 OSA is under-diagnosed: think of it in “tired all the time” patients, especially if obese and snoring.
- ⚠️ Always ask about driving – DVLA must be informed if OSA causes sleepiness.
- 🧠 Don’t forget secondary hypertension work-up should include OSA screening.
