What Are Asthma & COPD Exacerbations and Why Do They Matter in the ED?


An acute asthma exacerbation is a rapid or gradual worsening of asthma symptoms and lung function compared with baseline, triggered by infection, allergens, irritants or poor adherence. The BTS/SIGN–NICE asthma pathway and SIGN 158 set out definitions and severity criteria (moderate, acute severe, life-threatening, near-fatal). (Sign Language National Curriculum)


An acute exacerbation of COPD (AECOPD) is a sustained worsening of respiratory symptoms (usually breathlessness, cough, sputum volume/purulence) beyond normal day-to-day variation, requiring a change in treatment. NICE NG115 and GOLD 2024 are the key references. (NICE)


Asthma and COPD exacerbations are core ED conditions: they’re among the commonest causes of dyspnoea, ED attendances and admissions, and both carry significant morbidity and mortality. (em3.org.uk)


In the FRCEM SBA, these topics show up constantly as:


  • Bread-and-butter respiratory vignettes
  • ABG/oxygen interpretation questions
  • “Next best step” in acute asthma or COPD with hypercapnia
  • NIV indications and escalation to ICU


How Asthma & COPD Exacerbations Appear in the FRCEM SBA Exam


Common question angles:


  • Diagnosis / recognition
    • Distinguishing asthma vs COPD vs pneumonia vs PE vs LVF.
    • Recognising acute severe or life-threatening asthma (PEF %, RR, HR, SpO₂, ability to speak). (Beat Asthma)
    • Recognising a severe AECOPD with hypercapnic respiratory failure.


  • Initial investigation choice
    • When to do ABG vs VBG, peak flow, CXR, ECG.
    • Identifying ABG patterns (e.g. rising PaCO₂, worsening pH).


  • First-line management
    • Correct route/dose of bronchodilators and steroids.
    • Oxygen targets: 
      • Asthma: usually titrate to 94–98% unless CO₂ retainer. (BNF)
      • COPD exacerbation: 88–92% with controlled oxygen. (NCBI)


  • Complications / red flags
    • “Near-fatal” asthma, impending arrest, silent chest, exhaustion.
    • AECOPD with worsening acidosis/hypercapnia and indications for NIV/ICU. (NCBI)


Typical formats:

  • Classic adult asthma scenario with PEF and obs, asking “What is the severity class?” or “What is the best next management step?”
  • COPD exacerbation with ABG, asking about oxygen titration, NIV, or antibiotics (NICE NG114/115 antimicrobial thresholds). (NICE)
  • Image-based: CXR showing hyperinflation, pneumonia or pneumothorax as trigger.



Core Concepts You Must Know About Asthma & COPD Exacerbations


Definitions & Key Criteria


Asthma severity (adult ED) – from BTS/SIGN 158: (Beat Asthma)

  • Moderate: 
    • PEF >50–75% best/predicted
    • SpO₂ ≥92%
    • No features of acute severe asthma
  • Acute severe (any of): 
    • PEF 33–50% best/predicted
    • RR ≥25/min
    • HR ≥110/min
    • Inability to complete sentences in one breath
  • Life-threatening (any of): 
    • PEF <33% best/predicted
    • SpO₂ <92%
    • Silent chest, cyanosis, poor respiratory effort
    • Arrhythmia / hypotension
    • Exhaustion, confusion, coma, or raised PaCO₂


Near-fatal asthma = ICU ventilation for asthma ± hypercapnia.


COPD exacerbation – NICE NG115 / GOLD: (NICE)


  • Sustained worsening of cough, sputum volume/purulence and/or breathlessness.
  • Usually triggered by infection or environmental factors.
  • Severe/life-threatening if: 
    • Marked breathlessness, tachypnoea
    • Acute confusion
    • Cyanosis, peripheral oedema
    • ABG with acidosis (pH <7.35) and hypercapnia (PaCO₂ >6.0 kPa)
    • Hypoxaemia not corrected with controlled oxygen.



Assessment & Investigations


History and exam – shared themes

  • Onset & trigger: infection, exposure, allergen, missed inhalers.
  • Baseline: prior ICU admissions, previous NIV/intubation, home O₂, FEV₁, MRC dyspnoea.
  • Medication use: reliever frequency, oral steroids, theophylline, long-term antibiotics.
  • Co-morbidities: cardiac disease, OSA, obesity hypoventilation.


Asthma-specific assessment

  • PEF: compare to best or predicted.
  • SpO₂ and work of breathing: accessory muscles, speech, wheeze vs silent chest.
  • ABG/VBG: 
    • Early asthma: low PaCO₂ (hyperventilation).
    • Normal or rising PaCO₂ in a breathless patient is ominous.


COPD-specific assessment

  • Look for: 
    • CO₂ retainers (barrel chest, long COPD history, previous ABGs).
    • Cor pulmonale (oedema, raised JVP).
  • ABG: 
    • Acute exacerbation may cause acidosis + hypercapnia.
    • Chronic CO₂ retainers may have compensated respiratory acidosis baseline.
  • CXR: 
    • Hyperinflation, bullae, infection, pneumothorax, LVF.


NICE and GOLD emphasise ABG assessment in moderate–severe AECOPD and those with SpO₂ ≤92% on air or controlled oxygen. (NICE)


Initial ED Management


Asthma – acute management (adult)


BTS/SIGN and NICE-based approach: (Beat Asthma)

  • Oxygen: titrate to SpO₂ 94–98% (unless chronic CO₂ retainer).
  • Bronchodilators: 
    • High-dose inhaled SABA (e.g. salbutamol) via spacer or nebuliser.
    • Add ipratropium bromide for severe/life-threatening attacks.
  • Steroids: 
    • Oral prednisolone (e.g. 40–50 mg daily 5–7 days) or IV hydrocortisone if unable to swallow. (ScienceDirect)
  • Adjuncts in severe/life-threatening: 
    • IV magnesium sulphate. (rcemlearning.co.uk)
    • Consider IV salbutamol, senior/ICU involvement early.
  • Escalation: 
    • ICU if deteriorating: rising PaCO₂, falling pH, exhaustion, altered GCS, or cardiorespiratory arrest.


COPD exacerbation – acute management


NICE NG115, GOLD and ED guidance agree on the pillars: (NICE)

  • Oxygen: 
    • Controlled oxygen (Venturi mask) titrated to SpO₂ 88–92%.
  • Bronchodilators: 
    • Nebulised SABA ± SAMA (salbutamol + ipratropium).
  • Steroids: 
    • Oral prednisolone 30–40 mg once daily (typically 5 days). (NICE)
  • Antibiotics (if indicated): 
    • Per NICE NG114/NG115: prescribe if increased sputum purulence plus one of increased volume or increased dyspnoea, or if severe/systemically unwell. (NICE)
  • NIV: 
    • Indicated in COPD patients with persistent or worsening respiratory acidosis (pH ≤7.35, PaCO₂ >6.0 kPa) despite optimal medical therapy. (NCBI)
  • Intubation/ICU: 
    • Consider if NIV fails, or if contraindicated (copious secretions, facial trauma, inability to protect airway).


Red Flags and Pitfalls


Red flags that FRCEM loves:

  • Previous ICU admission/intubation for asthma or COPD.
  • Rising PaCO₂ with worsening fatigue in an asthmatic.
  • COPD patient on uncontrolled high-flow oxygen drifting into CO₂ narcosis.
  • Severe AECOPD failing to respond to optimised medical treatment within 1 hour → consider NIV.


Pitfalls:

  • Over-oxygenating COPD: ignoring 88–92% target and forgetting ABG review. (NCBI)
  • Underestimating near-silent chest in asthma.
  • Delaying steroids and magnesium in life-threatening asthma.
  • Calling pneumonia “COPD exacerbation” without treating the infection properly.



Special Populations


  • Asthma in pregnancy
    • Treat exacerbations as aggressively as non-pregnant patients; poorly controlled asthma is worse for mother and fetus than standard treatment.
  • Elderly COPD
    • May present with confusion and fatigue rather than dramatic breathlessness.
  • Overlap syndrome (asthma–COPD overlap)
    • Management often resembles COPD but with greater steroid responsiveness; exam stems may deliberately blur the line.


Common FRCEM SBA Traps Related to Asthma & COPD Exacerbations


“Question writers love to test the difference between X and Y…”

  • Asthma vs COPD vs LVF
    • Trap: Calling an elderly smoker with orthopnoea and bibasal crackles “COPD exacerbation”.
    • Fix: Look for past COPD diagnosis, wheeze vs crackles, CXR findings, BNP/echo.
  • Useful investigation vs best next step
    • Trap: Choosing CT pulmonary angiogram in a hypoxic, wheezy asthmatic before giving bronchodilators and steroids.
    • Fix: Stabilise and treat life-threatening asthma/COPD first; imaging later unless PE is overwhelmingly likely and patient is haemodynamically stable.
  • Oxygen targets
    • Trap: Giving non-rebreathe at 15 L/min to a known CO₂-retaining COPD patient and leaving it running despite rising PaCO₂.
    • Fix: Controlled oxygen, SpO₂ 88–92%, frequent ABGs and adjustment. (NCBI)
  • NIV indications
    • Trap: Starting NIV solely for hypoxaemia without hypercapnia/acidosis, or failing to escalate to NIV when pH is 7.28 with PaCO₂ 8.4 kPa despite optimal therapy. (NCBI)
  • Steroid dose/duration
    • Trap: Choosing long (14-day) pred courses routinely or unnecessary IV hydrocortisone for a patient who can swallow.
    • Fix: 5–7 days oral pred is usually sufficient in both asthma and COPD; IV only if oral not possible. (NICE)


High-Yield Clinical Patterns for Asthma & COPD Exacerbations in the ED


Classic Presentation – Adult Acute Severe Asthma

Age: 25-year-old with known atopic asthmaHistory: 12 hours of worsening wheeze, using salbutamol every 30–60 minutesObs:HR 120 bpmRR 30/minBP 130/80 mmHgSpO₂ 93% RAPEF 40% bestAble to speak in short phrases only

This is acute severe asthma (PEF 33–50%, RR ≥25, HR ≥110, can’t complete sentences). Expect questions on nebulised β₂-agonists, ipratropium, steroids, magnesium and disposition. (Beat Asthma)


Classic Presentation – COPD Exacerbation with Hypercapnic Failure


Age: 70-year-old man, FEV₁ 30% predictedHistory: 3 days of increased dyspnoea and sputum purulence; normally houseboundObs:HR 110 bpmRR 28/minBP 145/85 mmHgSpO₂ 84% RA → 90% on 28% VenturiABG on 28%: pH 7.29, PaCO₂ 8.1 kPa, PaO₂ 7.8 kPa, HCO₃⁻ 29 mmol/L


This is classic AECOPD with acute on chronic hypercapnic respiratory failure, likely needing NIV if acidosis persists after initial bronchodilators, steroids, antibiotics and optimised oxygen. (NCBI)


Atypical Presentation

  • Asthma without wheeze – “silent chest” and fatigue in a young adult who looks surprisingly calm but is tiring.
  • COPD with confusion – primary presenting feature is delirium; ABG reveals severe hypercapnia.


Dangerous Mimics


Differentials you must be able to separate:

  • PE – pleuritic pain, haemoptysis, disproportionate tachycardia, clear chest, risk factors.
  • Pneumothorax – unilateral pleuritic pain, reduced breath sounds, hyperresonance.
  • Acute LVF – crackles, S3, cardiomegaly, elevated BNP, orthopnoea.
  • Upper airway obstruction / anaphylaxis – stridor, facial swelling, urticaria.


How to Revise Asthma & COPD Exacerbations Efficiently for the FRCEM SBA


Use Question Banks First, Then Guidelines


  • Start with blocks of asthma and COPD SBAs: 
    • Mix adult and paeds, mild–life-threatening, ABG interpretation, NIV questions.
  • Then read the key guideline sections: 
    • BTS/SIGN/NICE asthma pathway (NG244/NG245/SIGN 158) for acute adult asthma in ED. (NICE)
    • NICE NG115/NG114 & GOLD for COPD exacerbations (bronchodilators, steroids, oxygen, NIV, antibiotics). (NICE)
    • RCEMLearning reference articles on asthma in adults and COPD for UK EM flavour. (rcemlearning.co.uk)



Build Mini-Notes or Flashcards from Mistakes


Each time you miss an asthma/COPD SBA:

  • Capture what the stem subtly hinged on: 
    • Severity classification (PEF %, RR, HR, SpO₂).
    • Oxygen targets.
    • NIV indications.
  • Then write a one-liner: 
    • “COPD with persistent pH ≤7.35 and PaCO₂ >6 despite optimal therapy → NIV.” (NCBI)
    • “Acute severe asthma: PEF 33–50%, RR ≥25, HR ≥110, can’t speak in full sentences.” (Beat Asthma)


These become ultra-high-yield cards in the final weeks.


Mix Text-Based and Image-Based Questions

  • Pair vignette SBAs with: 
    • CXR images (pneumonia, hyperinflation, pneumothorax).
    • Observation charts (SpO₂ and RR trends).
    • ABG data across time (pre/post oxygen or NIV).
  • Practise identifying: 
    • Who needs immediate escalation.
    • Who can be safely discharged with inhaler optimisation and follow-up.


How StudyMedical Covers Asthma & COPD Exacerbations in Its FRCEM SBA Question Bank


StudyMedical contains a large bank of curriculum-mapped asthma and COPD SBAs built around realistic ED scenarios, aligned to the RCEM 2021 curriculum and the FRCEM SBA blueprint.


For this topic specifically, you can highlight:

  • Full-vignette respiratory cases
    • Adult asthma, life-threatening asthma, status asthmaticus, moderate exacerbations, and mixed-dyspnoea cases where you must choose between asthma, COPD, PE, LVF, and pneumonia.
  • COPD exacerbation SBAs
    • Including ABG interpretation, oxygen titration to 88–92%, indications and contraindications for NIV, and decisions about antibiotics and steroids.
  • Image and data-based questions
    • CXR, obs charts, and ABGs woven into vignettes to mirror real exam style.
  • Guideline-anchored explanations
    • Referencing BTS/SIGN/NICE asthma guidance and NICE/GOLD COPD guidance, so answers tie directly to current recommendations. (NICE)
  • Smart revision modes
    • “New”, “Incorrect”, and “Flagged” modes so you can hammer your asthma/COPD weak spots on post-nights and pre-exam sprints.


FAQs About Asthma & COPD Exacerbations in the FRCEM SBA


How often do asthma and COPD questions appear in the FRCEM SBA?


Very frequently. Breathlessness is a top-tier ED presentation and asthma/COPD make up a large chunk of respiratory questions, both as primary diagnoses and as differentials.


What’s the single most important thing to remember for these topics?


For asthma: recognise severity and life-threatening features early and escalate quickly. For COPD: control oxygen to 88–92%, watch the ABG, and know when to start NIV.


Are there must-know guidelines or scores?

Yes:

  • BTS/SIGN/NICE asthma guidance (NG244, NG245, SIGN 158). (NICE)
  • NICE NG115/NG114 and GOLD 2024/2025 for COPD. (NICE)


How many asthma/COPD questions should I aim to do before the exam?


Aim for at least 50–100 dedicated asthma/COPD SBAs, plus many more mixed dyspnoea cases. These should feel like “free marks” by the time you sit the paper.


Key Takeaways: Asthma & COPD Exacerbations for FRCEM in 5 Bullet Points

  • Classify asthma severity correctly (moderate, acute severe, life-threatening) and know when to call ICU. (Beat Asthma)
  • Manage COPD with controlled oxygen and target SpO₂ 88–92%, not 100%. (NCBI)
  • Recognise when ABGs show impending failure – rising PaCO₂ and falling pH in both asthma and COPD. (bestpractice.bmj.com)
  • Know NIV indications in AECOPD (persistent respiratory acidosis despite optimal medical therapy). (NCBI)
  • Use high-quality SBAs plus guidelines (BTS/SIGN/NICE, GOLD) to make asthma and COPD questions automatic wins on the exam. (NICE)


Ready to Test Yourself on Asthma & COPD Exacerbations?


Asthma and COPD exacerbations are everyday ED problems and high-yield FRCEM SBA topics:

  • Mastering them improves both your exam score and your resus room performance.
  • The fastest route is to combine scenario-based SBAs with focused guideline reading.