MBBS OSCE · Respiratory / General Medicine

OSCE — assessment of an acute COPD exacerbation

An 8-minute OSCE station assessing the candidate's structured assessment, blood-gas interpretation, and immediate management of an acute COPD exacerbation with hypercapnic respiratory failure. Marks for controlled oxygen (SpO2 88-92%), the exacerbation medical bundle with doses, and the timely use of non-invasive ventilation.

8 min stationVerification in progress
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NEET-PGINICETUSMLEPLAB

Brief (to candidate)

A 68-year-old man with known COPD is brought in with 3 days of worsening breathlessness and yellow-green sputum. He is drowsy, respiratory rate 28, SpO2 86% on air, with wheeze and accessory-muscle use. An arterial blood gas on air shows pH 7.29, PaCO2 9.0 kPa (68 mmHg), PaO2 7.0 kPa, bicarbonate 32 mmol/L. You have 8 minutes to assess him, interpret the blood gas, and outline immediate management.

Candidate instructions

  1. Take a focused, structured history and examine using an ABCDE approach.
  2. Interpret the arterial blood gas and state the diagnosis.
  3. Outline the immediate management, including drug therapy with doses, routes, and timing, and the oxygen target.
  4. State the indication and settings for non-invasive ventilation, your disposition, and the discharge plan.

Examiner checklist (mark each domain / 10)

DomainKey actions expected
ABCDE / resuscitationAirway; controlled oxygen to SpO2 88–92% (states the CO2-narcosis rationale); IV access
Blood-gas interpretationRecognises acute-on-chronic type-2 respiratory failure (low pH, high PaCO2, raised bicarbonate)
Exacerbation bundleNebulised salbutamol 5 mg + ipratropium 500 µg; prednisolone 40 mg for 5 days[2]; antibiotic (Anthonisen type-1 — purulent sputum): amoxicillin-clavulanate/doxycycline
Non-invasive ventilationStates indication (pH below 7.35 / hypercapnia); typical settings (IPAP 10–15, EPAP 4–5 cmH2O); first-line, reduces intubation/mortality[3]
Precipitant searchActively looks for pneumonia, pneumothorax, PE (and treats if found)
Escalation / dispositionRepeats ABG at 30–60 min; escalates to ICU/invasive ventilation on NIV failure
Discharge & preventionInhaler-technique check; smoking cessation, vaccination, pulmonary rehab, written COPD action plan; consider LTOT assessment for chronic hypoxaemia

Model key actions

  • Controlled oxygen to SpO2 88–92% with rationale (Haldane effect / hypoxic drive); repeat ABG at 30–60 min.[1]
  • Nebulised salbutamol 5 mg + ipratropium 500 µg, prednisolone 40 mg for 5 days (REDUCE),[2] and an antibiotic (purulent sputum → Anthonisen criteria).
  • Start NIV (BiPAP) — pH 7.29 is acidotic hypercapnic failure; IPAP 10–15 / EPAP 4–5 cmH2O.[3]
  • Exclude pneumonia/pneumothorax/PE; escalate to invasive ventilation if NIV fails.

Common errors

  • Giving uncontrolled high-flow oxygen → CO2 narcosis.
  • Not recognising type-2 (hypercapnic) respiratory failure on the blood gas.
  • Delaying/withholding NIV when pH below 7.35 — NIV is first-line.
  • Missing the precipitant (pneumothorax, pneumonia, PE).
  • Omitting the prevention/discharge plan (smoking cessation, vaccination, action plan, LTOT assessment).
References3Show
  1. [1]Agustí A, et al. GOLD 2023 Report: Executive Summary. European Respiratory Journal, 2023.PMID 36858443
  2. [2]Leuppi JD, et al. Short-term vs conventional glucocorticoid therapy in acute exacerbations of COPD (REDUCE). JAMA, 2013.PMID 23695200
  3. [3]Plant PK, et al. Early non-invasive ventilation for acute exacerbations of COPD. Lancet, 2000.PMID 10859037
OSCE — assessment of an acute COPD exacerbation · MBBS OSCE · NeetVellum