1. Why this matters for MRCGP

• Acute asthma is a classic AKT “next best step” topic because the answer changes with severity, response to treatment, oxygen saturation, peak expiratory flow, age and home support.
• It is a strong SCA topic because the consultation is time-critical: assess, treat, explain risk, decide admission, and safety-net without over-reassurance.
• The key GP risk is missing severe asthma because the patient is not distressed or wheeze is absent.
• Practical use matters because safe care depends on correct salbutamol, spacer, nebuliser, oxygen, prednisolone and follow-up use.

2. GP Bottom Line

• Treat an emergency asthma presentation as potentially serious until severity is recorded objectively.
• Urgency changes with inability to speak/feed, oxygen saturation, peak expiratory flow, silent chest, exhaustion, confusion, poor respiratory effort, poor response, previous near-fatal asthma or unsafe home circumstances.
• Usual GP action is: assess severity, give prompt bronchodilator treatment, oxygen if available, early oral prednisolone, and arrange emergency transfer when severe, life-threatening or not responding.
• Do not treat this as “just poor control”: do not prescribe ongoing short-acting beta-2 agonist treatment without concomitant inhaled corticosteroid (ICS)-containing treatment; acute salbutamol remains first-line rescue treatment during an attack. Do not routinely prescribe antibiotics, and arrange review within 2 working days after an attack.

3. 60 Second Exam Snapshot

• Acute asthma exacerbation = acute or subacute worsening of symptoms and lung function from usual status.
• Record: consciousness, temperature, pulse, respiratory rate, blood pressure, oxygen saturation, speech/feeding, accessory muscle use, wheeze or silent chest, and peak expiratory flow if able.
• Peak expiratory flow should be the best of 3 readings, compared with personal best from the last 2 years if known, or predicted value.
• Adults: acute severe features include inability to complete sentences in one breath, respiratory rate ≥25/min, pulse ≥110/min, or peak expiratory flow 33–50% best/predicted.
• Children: acute severe features include too breathless to talk/feed, accessory neck muscle use, oxygen saturation below 92%, peak expiratory flow 33–50% where measurable, or age-specific tachycardia/tachypnoea.
• Life-threatening features include silent chest, cyanosis, poor respiratory effort, exhaustion, confusion/altered consciousness, hypotension, oxygen saturation below 92% in severe context, or peak expiratory flow below 33%.
• Follow-up is not optional: review within 2 working days, check inhaler technique/adherence, and update the personalised asthma action plan.

4. Recognition and Diagnosis

• Think acute asthma when a person with known or suspected asthma has worsening breathlessness, wheeze, cough or chest tightness. They may present for the first time during an exacerbation.
• Do not rely on wheeze. Wheeze may become biphasic or disappear as obstruction worsens; a “silent chest” is dangerous. Also do not rely on visible distress: severe or life-threatening exacerbations may not look dramatic.
• Check for alternative acute causes of breathlessness such as pulmonary embolism, pneumothorax or pneumonia. The asthma diagnosis may be uncertain, but if the person is acutely unwell or highly symptomatic, treat immediately and arrange objective asthma tests later when symptoms are controlled.
• Oxygen saturation below 92% on air is high risk in acute asthma and should prompt emergency-level assessment and escalation according to severity and response.

5. AKT Essentials: What Changes the Answer

Diagnosis / recognition

• Variable asthma symptoms worsening acutely or subacutely.
• May be first presentation of asthma.
• Absence of wheeze does not reassure if airflow is severely reduced.

Severity / urgency

• Moderate adult: increasing symptoms, peak expiratory flow above 50–75% best/predicted, no acute severe features.
• Moderate child: talking in sentences, oxygen saturation at least 92%, peak expiratory flow above 50% if measurable, pulse and respiratory rate below severe thresholds.
• Acute severe adult: inability to complete sentences in one breath, respiratory rate ≥25/min, pulse ≥110/min, or peak expiratory flow 33–50%.
• Acute severe child: too breathless to talk or feed, accessory neck muscle use, oxygen saturation below 92%, peak expiratory flow 33–50%, pulse over 140 aged 2–5 or over 125 if over 5, respiratory rate over 40 aged 2–5 or over 30 if over 5.
• Life-threatening: silent chest, cyanosis, poor respiratory effort, exhaustion, drowsiness/confusion/altered consciousness, hypotension, peak expiratory flow below 33%, or oxygen saturation below 92% with severe features.

Management / next best step

• Life-threatening: emergency treatment while arranging emergency transfer to hospital.
• Acute severe not responding to initial treatment: emergency hospital admission.
• Moderate: treat initially in primary care, then transfer if worsening or not responding.
• Home management after moderate exacerbation only if symptoms improve, peak expiratory flow improves to more than 60–80% best/predicted, oxygen saturation on air is above 94%, and the person can cope at home with support.

Medicines / safety

• Salbutamol is the key short-acting beta-2 agonist used acutely.
• Nebulised ipratropium bromide is added in life-threatening asthma or poor response to initial beta-2 agonist treatment.
• Give oral prednisolone early.
• Do not routinely prescribe antibiotics.
• Do not prescribe ongoing short-acting beta-2 agonist treatment without concomitant ICS containing treatment; acute salbutamol remains first line rescue treatment during an attack.

Follow-up / monitoring

• Review within 2 working days after any exacerbation.
• Reassess symptoms and signs, need for further prednisolone, triggers, modifiable risks, inhaler technique, adherence and action plan.

6. SCA Consultation Essentials

This is usually an urgent same-day consultation, not a routine asthma review. The task is to decide: can this person stay in primary care after treatment, or do they need emergency transfer?

Gather quickly:

• Can they speak in sentences? In a child, can they talk or feed?
• What are oxygen saturation, respiratory rate, pulse, blood pressure and consciousness level?
• Is there accessory muscle use, cyanosis, exhaustion, silent chest or poor respiratory effort?
• What is the peak expiratory flow, if old enough and well enough?
• What reliever have they used, how often, and did it work?
• Are they already taking oral corticosteroids?
• Any previous near-fatal asthma, emergency attendance, admission, ventilation or recent severe attack?
• Can they safely cope at home if they improve?

Communication pivot: explain that asthma attacks can deteriorate quickly and that the decision is based on measured severity and response, not just how anxious or wheezy they look.

Specific safety netting should include what to do if symptoms worsen, do not respond to maximum reliever use, or recur before review.

7. Red Flags / Escalation / Referral

Arrange emergency transfer to hospital if there are:

• Any life threatening features.
• Acute severe features that persist after initial treatment.
• Deterioration, poor response or worsening response at any time.
• Previous near fatal asthma.
• Unsafe home management.
• A child with severe or life threatening features, or inadequate response to treatment.

Have a lower threshold for hospital admission or referral if the attack occurs in the evening/night, there are social or coping concerns, recent severe attacks, or an attack despite adequate oral corticosteroids.

If admitting, give emergency treatment, stay with the patient until the ambulance arrives, and send written assessment and referral details.

This Topic Essential does not cover children under 2 years. Acute asthma treatment in this age group should be managed in hospital, with treatment in children under 1 year directed by a respiratory paediatrician.

8. What the GP Should Do Today

Assess

• Record severity immediately: consciousness, pulse, respiratory rate, blood pressure, oxygen saturation, speech/feeding, accessory muscle use, wheeze or silent chest, and peak expiratory flow if possible.

Treat

• Oxygen if available, aiming for saturation 94–98%. Do not delay oxygen if pulse oximetry is unavailable.
• Moderate attack: salbutamol by pressurised metered dose inhaler plus large volume spacer, reassessing response.
• Severe or life threatening attack: nebulised salbutamol, preferably oxygen-driven. Add nebulised ipratropium bromide in life threatening asthma or poor response.
• If a nebuliser is not available, give salbutamol by pressurised metered dose inhaler and large volume spacer, one puff at a time according to response up to 10 puffs, while arranging urgent transfer if indicated.
• Give oral prednisolone early.

Refer

• Transfer urgently if severe, life threatening, worsening or not responding.

If managed at home after response

• Only do this after clear improvement, peak expiratory flow above 60–80% best/predicted, oxygen saturation on air above 94%, and adequate home support. Continue prednisolone until recovery, check inhaler technique and adherence, update the asthma action plan, and arrange review within 2 working days.

9. Practical Use in GP: How to Apply This Topic

Before use

• Confirm age, severity, current inhalers, action plan, prior reliever response and previous severe attacks.
• Check peak expiratory flow only if the person is old enough and well enough.

Salbutamol by spacer

• For pressurised metered-dose inhaler use, remove the mouthpiece cover fully, check the mouthpiece is clear, shake the inhaler, and give one puff at a time through the spacer.
• Each puff should be inhaled separately using tidal breathing.
• Give another puff every 60 seconds according to response, up to 10 puffs.

Nebulised bronchodilator

• Use nebulised salbutamol for severe/life-threatening attacks or poor response where indicated.
• Salbutamol 5 mg in adults and children over 5; 2.5 mg in children aged 2–5.
• Repeat nebulised bronchodilator every 20–30 minutes if response is inadequate.
• Add nebulised ipratropium bromide in life-threatening asthma or poor initial response: 0.5 mg in adults, 0.25 mg in children aged 2–12.
• If a nebuliser is not available, give salbutamol by pressurised metered-dose inhaler and large-volume spacer, one puff at a time according to response up to 10 puffs, while arranging urgent transfer if indicated.

Prednisolone

• Adults and children 16 years and over: 40–50 mg.
• Children 6–15 years: 30–40 mg.
• Children 2–5 years: 20 mg.
• Continue until recovery: minimum 5 days in adults/16+, and minimum 3–5 days in children.
• Tapering is not needed if prescribed for less than 2 weeks.
• Do not stop inhaled corticosteroids while taking oral prednisolone.

Patient action during an attack

• Blue reliever inhaler: 1 puff every 30–60 seconds up to 10 puffs.
• For patients already prescribed anti-inflammatory reliever or maintenance and reliever therapy, follow the personalised asthma action plan and do not exceed the inhaler’s maximum licensed daily dose. If symptoms are not controlled after the action-plan reliever steps, or worsen at any time, call 999.
• Call 999 if worse at any time, not better after maximum reliever use, or no inhaler is available.
• If no better after 10 minutes and ambulance has not arrived, repeat up to the same maximum dose.
• Do not drive to A&E.
• For adults aged 17 years and over using low-dose ICS maintenance in a single inhaler, a personalised action plan may include increasing the ICS dose for 7 days, considering quadrupling the regular dose without exceeding the maximum licensed daily dose.

What not to do

• Do not put multiple puffs into the spacer at once.
• Do not routinely prescribe antibiotics.
• Do not use montelukast for an acute attack.
• Do not support home nebuliser rescue treatment in children unless initiated and managed by an asthma specialist.
• Do not sedate a patient with an acute asthma attack unless this is to allow anaesthetic or intensive-care procedures.

10. Medicines, Investigations and Intervention Safety

• Salbutamol / short-acting beta-2 agonist: Use acutely by inhaler and spacer or nebuliser. Cautions include arrhythmias, cardiovascular disease, diabetes, hypertension, hyperthyroidism, hypokalaemia and susceptibility to QT interval prolongation. In severe asthma, monitor potassium because beta-2 agonists can reduce potassium, especially with high doses.
  • Overuse matters: increased use may mask deterioration and is linked with severe exacerbations, hospitalisation and mortality. Review and adjust treatment if as-needed short-acting beta-2 agonist is needed more than twice weekly. Do not prescribe ongoing short-acting beta-2 agonist treatment without concomitant ICS-containing treatment; acute salbutamol remains first-line rescue treatment during an attack.
• Inhaled corticosteroid: Do not stop during oral prednisolone. Check adherence and technique after the attack. If using a pressurised metered-dose inhaler, a spacer is usually prescribed, especially in children.
• Prednisolone: Give early in acute asthma. Short acute courses do not need tapering within the supported limits. Frequent or long-term oral corticosteroid courses need monitoring for cumulative adverse effects.
• Ipratropium bromide and parenteral corticosteroid alternatives: Nebulised ipratropium bromide is added for life-threatening asthma or poor response to initial beta-2 agonist treatment. If oral prednisolone cannot be given, emergency alternatives include IM methylprednisolone 160 mg for adults, or IV hydrocortisone 100 mg for adults/children aged 5 years and over, and 50 mg for children aged 2–4 years.
• Peak expiratory flow: Use the best of three readings if the patient is old enough and well enough. Compare with personal best from the last 2 years if available, otherwise predicted.
• Interventions not initiated in GP: Intravenous magnesium sulphate, intravenous aminophylline, intravenous salbutamol and critical-care treatments are hospital/senior specialist escalation interventions.

11. How to Explain It to the Patient

• “This is an asthma attack, which means your breathing and lung function have worsened from your usual level.”
• “I’m checking your oxygen level, breathing rate, pulse, speech and peak flow because these tell us how serious this is.”
• “Use the spacer one puff at a time; each puff needs to be breathed in separately.”
• “The steroid tablets reduce the attack and help prevent it coming back; keep using your inhaled steroid as well.”
• “If you get worse, or you are not better after the maximum reliever dose, call 999.”
• “Even if you feel better today, we need to review you within 2 working days to reduce the risk of another attack.”

12. When the Plan Changes

• If: oxygen saturation is below 92%, peak flow is below 33%, there is silent chest, cyanosis, confusion, exhaustion or poor respiratory effort.
  • Why this changes the plan: these are life-threatening features.
  • What the GP does now: give emergency treatment and arrange emergency transfer.
• If: acute severe features persist after initial treatment.
  • Why this changes the plan: primary care treatment has not reversed the risk.
  • What the GP does now: arrange emergency hospital admission.
• If: moderate exacerbation improves after initial treatment.
  • Why this changes the plan: home management may be possible only if objective and social criteria are met.
  • What the GP does now: confirm oxygen saturation above 94%, peak flow improving to more than 60–80%, ability to cope at home, prednisolone plan and 2 working day review.
• If: the patient is using a blue reliever frequently or has increased prescription requests.
  • Why this changes the plan: short acting beta-2 agonist overuse may mask deterioration.
  • What the GP does now: review urgently, check preventer collection/adherence, and ensure ICS containing treatment.
• If: the patient asks for antibiotics.
  • Why this changes the plan: asthma attacks are not treated with routine antibiotics.
  • What the GP does now: treat the asthma attack and only consider infection management if separately indicated by assessment.

13. Common AKT / SCA Traps

• Reassuring because the patient is not distressed.
• Missing silent chest.
• Forgetting oxygen saturation, pulse, respiratory rate or peak flow.
• Using predicted peak flow when recent personal best is available.
• Sending home without good response, oxygen saturation above 94%, improving peak flow and home support.
• Giving all spacer puffs at once.
• Prescribing antibiotics routinely.
• Prescribing ongoing short acting beta-2 agonist treatment without ICS containing treatment.
• Using montelukast as acute rescue treatment.
• Sedating a patient with acute asthma outside anaesthetic or intensive care procedures.
• Forgetting review within 2 working days.

14. Common Exam Angles

• Angle: Breathless adult with asthma in a same day GP slot.
  • Hidden challenge: they are calm but cannot complete sentences.
  • What the candidate must not miss: acute severe asthma needs emergency level action if not responding.
• Angle: Child with wheeze and parent requesting “just a nebuliser at home”.
  • Hidden challenge: home nebuliser rescue treatment in children needs specialist initiation and monitoring.
  • What the candidate must not miss: assess severity, use spacer/nebuliser appropriately, and escalate if poor response.
• Angle: Patient has recovered after an attack and wants no review.
  • Hidden challenge: relapse risk and preventable future attacks.
  • What the candidate must not miss: review within 2 working days, inhaler technique, adherence and action plan.
• Angle: Frequent blue inhaler requests.
  • Hidden challenge: short-acting beta-2 agonist overuse.
  • What the candidate must not miss: do not prescribe ongoing short acting beta-2 agonist treatment without ICS containing treatment, and review treatment urgently.

15. 90 Second Audio Summary Script

Acute asthma in general practice is about rapid severity assessment and safe escalation. Do not be reassured by a calm patient or by absent wheeze. Severe airflow obstruction can produce a silent chest, and some severe attacks do not look dramatic.

Record the basics: consciousness, pulse, respiratory rate, blood pressure, oxygen saturation, ability to speak or feed, accessory muscle use, wheeze or silent chest, and peak flow if the person is old enough and well enough. Use the best of three peak flow readings and compare with personal best if available.

The danger features are inability to complete sentences, a child too breathless to talk or feed, oxygen saturation below 92%, peak flow 33–50% for acute severe and below 33% for life threatening, silent chest, cyanosis, poor respiratory effort, exhaustion, confusion or hypotension.

Treat promptly. Oxygen aims for 94–98%. Use salbutamol early: spacer for moderate attacks, nebulised treatment for severe or life threatening attacks or poor response. If a nebuliser is unavailable, use a pressurised metered dose inhaler and large volume spacer while arranging urgent transfer if indicated. Add ipratropium for life threatening asthma or poor response. Give oral prednisolone early, and do not stop inhaled corticosteroids.

A moderate attack can only go home after good response, improving peak flow, oxygen saturation above 94%, and safe home support. Do not routinely prescribe antibiotics. Do not sedate acute asthma unless this is for anaesthetic or intensive-care procedures. Do not prescribe ongoing short acting beta-2 agonist treatment without ICS containing treatment; acute salbutamol remains first-line rescue treatment during an attack. Review every exacerbation within 2 working days, check inhaler technique and adherence, and update the asthma action plan.

References

1. British Thoracic Society and Scottish Intercollegiate Guidelines Network (2019) British guideline on the management of asthma: SIGN 158. Edinburgh: SIGN. Available at: https://www.sign.ac.uk/guidelines/british-guideline-on-the-management-of-asthma/ (Accessed: 28 April 2026).
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9. Medicines and Healthcare products Regulatory Agency (2018) Pressurised metered dose inhalers (pMDI): risk of airway obstruction from aspiration of loose objects. Drug Safety Update, 17 July. Available at: https://www.gov.uk/drug-safety-update/pressurised-metered-dose-inhalers-pmdi-risk-of-airway-obstruction-from-aspiration-of-loose-objects (Accessed: 28 April 2026).
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Important Disclaimer

This MedDigest MRCGP Topic Essentials is an independent educational and revision resource, created to support exam preparation only. It is not a clinical guideline, prescribing resource, or a substitute for your own professional judgment.

This content is designed to highlight exam-relevant clinical principles, management pathways, and consultation approaches in a concise format. Any example explanations, consultation wording, scenario angles, or summary scripts are illustrative and should not be used as stand-alone clinical advice.

This resource has not been produced, reviewed, or endorsed by NICE, the Royal College of General Practitioners, or any other official organisation.

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