Makindo Medical Notes

😴 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)

📖 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.