1. Asthma

📄Definition

Chronic inflammatory airway disease with:

  • Reversible airflow obstruction

  • Airway hyperresponsiveness

  • Often linked to atopy and environmental triggers

Mnemonic: AIR

Airway inflammation
Intermittent symptoms
Reversible obstruction

🧬 Pathophysiology

  • Trigger (allergen, infection, exercise, cold air) → immune activation

  • Mast cells → histamine, leukotrienes → bronchial smooth muscle contraction

  • Eosinophils (IL-5 driven) → airway inflammation

  • Mucosal oedema + mucus hypersecretion → narrowed airways

🛡️ Risk Factors (Mnemonic: ASTHMIC)

  • Atopy (eczema, hay fever)

  • Smoking (active/passive)

  • Triggers (cold, dust, pets, pollen)

  • Household irritants (mould, damp)

  • Medications (NSAIDs, β-blockers)

  • Infections (esp. viral in childhood)

  • Childhood/family history

🤒 Symptoms (Mnemonic: WHACK)

  • Wheeze (expiratory, polyphonic)

  • Heavy chest (tightness)

  • At night/early morning (worse)

  • Cough (often dry, variable)

  • Keen trigger sensitivity (exercise, pets, dust, cold)

Symptoms are episodic and worse on exertion or allergen exposure.

🚩 Red Flags / Severe Features

  • Silent chest, exhaustion, confusion → impending respiratory failure

  • Life-threatening asthma: SpO₂ <92%, PEF <33%, silent chest, cyanosis, arrhythmia, hypotension

  • Near-fatal asthma: Raised PaCO₂ or need for mechanical ventilation

🔬 Investigations 

TestUseExam Notes
Spirometry with reversibilityObstructive pattern (FEV₁/FVC <70%) + ≥12% & ≥200 ml ↑ FEV₁ post-bronchodilatorDiagnostic gold standard
Peak flow monitoringVariability >20% = diagnosticDiurnal variation: morning dipping worse
FeNORaised in eosinophilic inflammationNICE recommends in uncertain cases
Allergy testingRAST/skin prick if atopy suspectedNot first-line
BloodsMay show eosinophiliaRule out differentials
CXRIf atypical / to exclude pneumoniaOften normal in asthma

🎯 EXAM ANCHOR 1 – DIAGNOSIS

  • Asthma diagnosis requires evidence of variable airflow obstruction

  • Reversibility ≥12% AND ≥200 mL increase in FEV₁ post-bronchodilator = asthma

  • Normal spirometry does not exclude asthma (repeat or peak flow diary)

📌 PARA commonly asks:

Which investigation confirms asthma?

👉 Answer: Spirometry with bronchodilator reversibility

🩻 CXR Findings (Mnemonic: THUMP)

  • Thickened bronchial walls

  • Hyperinflated lungs (flattened diaphragms)

  • Unusual findings suggest another cause

  • Mediastinal shift (if tension pneumothorax)

  • Pneumothorax / pneumomediastinum

🎯 EXAM ANCHOR 2 – ASTHMA vs COPD

  • Asthma = reversible obstruction

  • COPD = fixed/irreversible obstruction

  • Asthma often:

    • Younger onset

    • Atopy

    • Diurnal variability

📌 PARA commonly asks:

Which feature best differentiates asthma from COPD?

📊 Severity of Acute Asthma (BTS/NICE)

ClassificationFeatures
ModeratePEFR 50–75%, speaks in full sentences
SeverePEFR 33–50%, RR >25, HR >110, can’t finish sentences
Life-threateningPEFR <33%, SpO₂ <92%, silent chest, cyanosis, confusion, hypotension

🎯 EXAM ANCHOR 3 – ACUTE SEVERITY

  • PEF <33% = life-threatening asthma

  • Raised PaCO₂ = near-fatal asthma

  • Silent chest = impending respiratory failure

📌 PARA commonly asks:

Which feature indicates life-threatening asthma?

🎯 EXAM ANCHOR 3 – ACUTE SEVERITY

  • Life-Threatening “Normality”: A “normal” PaCO₂ (4.6–6.0 kPa) during an acute asthma attack is life-threatening.

  • It indicates respiratory muscle exhaustion — the patient can no longer hyperventilate to blow off CO₂.

  • A raised PaCO₂ signifies near-fatal asthma and impending ventilatory failure.

📌 PARA commonly asks:

A 24-year-old female presents to A&E with an acute asthma exacerbation. She is unable to complete sentences and has a respiratory rate of 30/min. An Arterial Blood Gas (ABG) is performed on room air. Which of the following ABG results is the MOST concerning sign of life-threatening exhaustion?

Stepwise Management (NICE 2022 Update)

Key Shift: MART Preferred

MART (Maintenance and Reliever Therapy) is now first-line for many adults and young people using:

  • Low-dose ICS-formoterol as both daily preventer and reliever
    (e.g. Fostair, Symbicort)

🎯 EXAM ANCHOR 4 – FIRST-LINE PREVENTER (BIG PARA SHIFT)

  • Low-dose ICS-formoterol (MART) is preferred first-line in adults

  • SABA alone is no longer first-line if preventer indicated

  • Always review inhaler technique before stepping up

📌 PARA commonly asks:

What is the preferred first-line preventer strategy in adult asthma?

👉 Answer: MART (ICS-formoterol)

Mnemonic: SMART PLAN

  • SABA no longer routinely used if on MART
  • MART preferred for many (ICS-formoterol)
  • Add-on therapy if uncontrolled: LTRA, ↑ICS
  • Review inhaler technique and adherence
  • Tailor plan to patient age and symptom pattern
  • Personalised asthma action plan
  • Low-dose ICS if not suitable for MART
  • Adult vs child algorithms differ
  • NICE stepwise diagram guides escalation
 

📋 Stepwise Treatment Ladder

🎯 EXAM ANCHOR 5 – WHEN TO START ICS

  • Start ICS if:

    • Symptoms ≥3 times/week

    • Night-time waking

    • Exacerbation requiring oral steroids

📌 PARA trap:

SABA-only treatment is not sufficient for frequent symptoms

 

StepTreatmentNotes
1MART (low-dose ICS–formoterol) daily + PRNPreferred adult first-line
2Add LTRA (montelukast) before Increase ICS doseWatch behavioural SE
3Switch to alternative inhaler regimen or ↑ICSSpecialist review if uncontrolled
Children <5SABA trial → daily ICS if frequentMART not licensed

Offer a structured review to people with asthma at least annually.
More frequent reviews may be needed after treatment changes or exacerbations.

🎯 EXAM ANCHOR 6 – PAEDIATRIC TRAP

  • MART is NOT licensed in children <5

  • Different algorithms for children vs adults

📌 PARA commonly asks:

Which asthma management option is inappropriate in a 4-year-old?

🚨 Acute Asthma Management (Mnemonic: O SHIT ME)

Oxygen (aim SpO₂ 94–98%)
Salbutamol (neb or inhaler)
Hydrocortisone IV / Prednisolone PO
Ipratropium (neb, esp. in severe)
Theophylline (specialist input only)
Magnesium sulfate IV (for life-threatening cases)
Escalate care → HDU/ICU if deteriorating

🎯 EXAM ANCHOR 7 – ACUTE ASTHMA MANAGEMENT

  • Use oxygen to drive nebulisers in acute severe or life-threatening asthma

  • Add ipratropium in severe/life-threatening asthma

  • IV magnesium sulfate for life-threatening asthma

  • Early steroids reduce relapse and admission

📌 PARA commonly asks:

First-line management of acute severe asthma?

Monitoring & Review

  • Annual asthma review

  • Personalised Asthma Action Plan (PAAP)

  • Check inhaler technique and trigger control

  • Consider stepping down therapy if controlled for ≥3 months

⚠️ Complications

Mnemonic: RAMP
Respiratory failure
Air leaks – pneumothorax or pneumomediastinum
Mucus plugging
Persistent hypoxaemia

❓ Differential Diagnoses (Mnemonic: VACUUM)

  • Vocal cord dysfunction

  • Anaphylaxis

  • COPD

  • Upper airway obstruction

  • Undiagnosed cardiac disease (HF)

  • MSK chest pain

🔎 Key PARA Exam Traps

    • Reversibility (≥12% AND ≥200 mL FEV₁) = asthma; irreversible airflow obstruction = COPD

    • Life-threatening asthma signs: silent chest, PEF <33%, SpO₂ <92%

    • Near-fatal asthma = raised PaCO₂ or need for ventilation

    • Always give oxygen with nebulised salbutamol (never air)

    • If LTRA ineffective, stop it and increase ICS or add LABA (do not continue ineffective LTRA – NICE)

    • Start ICS early if SABA ≥3 times/week

    • Montelukast → behavioural / neuropsychiatric side effects

    • ICS inhalers → rinse mouth to prevent oral candidiasis

    • MART regimen is for adults only

    • Cardioselective β-blockers (e.g. bisoprolol) may be used with caution — exam trap

    • Acute asthma + normal PaCO₂ (4.6–6.0 kPa) = respiratory muscle exhaustion → impending ventilatory failure

    • Montelukast + nightmares / suicidal ideation → stop immediately (MHRA)

    • Smoking reduces spirometry reliability; poor reversibility ≠ no asthma

📅 Last updated in line with:

  • NICE NG80 (Asthma: diagnosis, monitoring and chronic management) – Nov 2022

  • BTS/SIGN Asthma Guideline – 2019

  • PARA-aligned, reviewed February 2026

PASSMAP ensures all content is NICE-aligned and exam-optimised for the Physician Associate Regulation Assessment (PARA).

Educational platform. Not medical advice.

 

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