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Stem
A 54-year-old male lorry driver presents to the outpatient clinic. His wife reports that he snores loudly every night, stops breathing for what seem like "ages" and then gasps. He has gained 12 kg over two years (current BMI 39, neck circumference 44 cm), has recently been diagnosed with hypertension (BP 156/96 despite amlodipine 10 mg daily) and new-onset type 2 diabetes. He admits to falling asleep at traffic lights and once briefly while driving on a motorway. Epworth Sleepiness Scale is 17/24.
Questions
a) What is the most likely diagnosis, and which single screening questionnaire would you use at the bedside? State its components. (3 marks)
Diagnosis: obstructive sleep apnoea (OSA / OSAHS) — loud snoring, witnessed apnoeas, daytime sleepiness, obesity, resistant hypertension and falling asleep driving are the classical cluster.
Screening tool: STOP-BANG:
- Snoring (loud)
- Tiredness (daytime sleepiness)
- Observed apnoeas (witnessed)
- high blood Pressure (over 140/90 or treated)
- BMI over 35
- Age over 50
- Neck circumference over 40 cm
- male Gender
Score 0–2 low risk, 3–4 intermediate, 5–8 high risk. This patient scores 8/8 = high risk.
b) What is the definitive investigation, and how would you grade the severity once it is performed? (2 marks)
Definitive test: polysomnography (in-lab attended, or home sleep apnoea testing if high pre-test probability and no major comorbidity). It quantifies the apnoea-hypopnoea index (AHI) — apnoeas plus hypopnoeas per hour of sleep.
AASM severity grading: mild 5–15, moderate 15–30, severe over 30 events per hour. An apnoea is cessation of airflow for 10 s or more despite ongoing respiratory effort; a hypopnoea is a fall in airflow of at least 30% for 10 s or more with at least 3% desaturation or an arousal.
c) What is the gold-standard treatment, how is it defined as "effective", and what are the three most useful adherence-support measures? (3 marks)
Gold-standard first-line for moderate-severe OSA: continuous positive airway pressure (CPAP), typically 4–20 cmH2O (auto-titrating or fixed), which pneumatically splints the upper airway open.
"Effective" use is defined as CPAP used for at least 4 hours per night on at least 70% of nights.
Three adherence-support measures: (1) expert mask fitting (try nasal, full-face, nasal-pillows); (2) heated humidification to reduce nasal dryness/congestion; (3) ramp feature and pressure relief on exhalation (C-Flex/EPR), with structured early follow-up and troubleshooting.
d) List the four immediate non-pharmacological management priorities for this specific patient. (2 marks)
- Immediate driving cessation — advise him to stop driving and notify the licensing authority (DVLA in the UK) until assessed and effectively treated; he is a group 2 (HGV) licence holder with sleepiness at the wheel — a medico-legal obligation.
- Weight loss — the most effective reversible intervention; a 10% weight loss cuts AHI by ~20–30%; refer to dietetics and consider bariatric surgery (BMI over 35 with comorbidities).
- Avoid alcohol and sedatives before bed (they relax the pharyngeal dilators and worsen OSA); review his antihypertensive regimen.
- Lateral sleep positioning (positional therapy) and treat any nasal obstruction — while awaiting CPAP titration.