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Acute Asthma Exacerbation vs Poor Control
How to assess asthma severity at the pharmacy counter, when to call 999, when to arrange emergency hospital assessment, and when emergency supply or PGD supply is appropriate.
Why this matters
Asthma affects around 5.4 million people in the UK, and community pharmacists regularly encounter patients during both acute exacerbations and periods of worsening day-to-day control.1 These situations require different responses. Life-threatening asthma requires 999 immediately. Acute severe asthma also requires emergency hospital assessment: from a community pharmacy setting, this means calling 999 unless an immediately safe clinical transfer pathway has been agreed locally. A patient whose symptoms are deteriorating over days or weeks needs same-day GP review rather than repeated purchases of reliever inhalers.
Key severity markers are peak expiratory flow (PEF), oxygen saturation, respiratory rate, pulse, visible work of breathing, and the ability to complete a sentence.1 A normal oxygen saturation does not exclude acute severe asthma: always assess all markers together. A silent chest, where there is almost no air entry despite obvious respiratory effort, is a life-threatening sign. These adult severity thresholds do not apply directly to children, who may deteriorate more rapidly and require age-specific assessment.
NICE NG245 (2024) no longer recommends prescribing a short-acting beta-agonist (SABA) reliever without a concomitant inhaled corticosteroid or preventer therapy.1, 4 Many patients are now prescribed combination inhalers as Anti-inflammatory Reliever (AIR) or Maintenance and Reliever Therapy (MART). Before dispensing or advising on reliever use, confirm what the patient has been prescribed and whether they have an inhaled corticosteroid or maintenance treatment in place.
Red flags vs more likely benign
| Feature | More likely benign | Red flag ⚠ |
|---|---|---|
| Wheeze | Audible, bilateral wheeze without distress | Silent chest with minimal air entry despite effort: life-threatening, call 9991 |
| PEF | Above 75 percent of best or predicted | Below 50 percent: acute severe, call 999 for emergency hospital assessment. Below 33 percent: life-threatening, call 9991 |
| Speech | Able to speak in full sentences | Unable to complete sentences in one breath: acute severe, call 9991 |
| Respiratory rate | 12 to 20 breaths per minute at rest | 25 breaths per minute or more: acute severe (adult threshold)1 |
| Pulse | Below 100 beats per minute | 110 beats per minute or more: acute severe (adult threshold)1 |
| Oxygen saturation (SpO2) | 95 percent or above on air. Normal SpO2 does not exclude acute severe asthma: always assess with PEF, speech, and respiratory rate | Below 92 percent on air: life-threatening. Administer emergency oxygen targeting 94 to 98 percent if trained staff and equipment are available, and call 9991 |
| Response to reliever | Clear improvement within 15 to 20 minutes | No improvement or worsening after 10 puffs via spacer: call 999 immediately1 |
| Reliever use | Occasional use with stable control | Three or more times per week: poor control, GP review needed.2 Three or more SABA inhaler prescriptions per year indicates overuse and is associated with increased risk of severe exacerbations, hospitalisation, and mortality3, 4 |
| Night-time symptoms | Sleep undisturbed | Night-time waking one or more times a week with wheeze or cough: poor control by BTS/NICE/SIGN criteria, GP review needed1 |
| Consciousness | Alert and oriented | Confusion, exhaustion, drowsiness or collapse: life-threatening, call 9991 |
What to do in pharmacy
Call 999 immediately for life-threatening features: silent chest; SpO2 below 92 percent on air; PEF below 33 percent of best or predicted; no response or worsening after 10 puffs of salbutamol via spacer; cyanosis, confusion, exhaustion, drowsiness, collapse or bradycardia.1 Where trained staff, suitable equipment, medicines governance, and a local standard operating procedure (SOP) are in place, administer emergency oxygen targeting SpO2 94 to 98 percent while awaiting the ambulance. Give salbutamol 5 mg via nebuliser; add ipratropium 0.5 mg nebulised for life-threatening asthma or poor response to initial salbutamol, where your local SOP and professional competence permit.1 Otherwise give 10 puffs salbutamol via spacer and repeat every 20 minutes. For acute severe features without immediately life-threatening signs (PEF 33 to 50 percent, inability to complete sentences, respiratory rate 25 or more per minute, or pulse 110 or more per minute), treat this as requiring emergency hospital assessment: call 999 unless an immediately safe clinical transfer pathway has been agreed locally, and continue salbutamol en route.1 Do not allow the patient to travel alone or to drive themselves to hospital. Document all actions, the time of assessment, severity markers observed, treatment given, and the escalation decision.
Arrange same-day GP review (within the same working session) for: PEF between 50 and 75 percent combined with no improvement on the usual reliever; increasing reliever use over recent days suggesting a deteriorating exacerbation; a patient who has completed an oral corticosteroid course in the past four weeks.1 Contact the GP practice directly where possible, document the discussion, and advise same-day assessment rather than leaving the patient to self-refer. Poor inhaled corticosteroid adherence, repeated reliever requests, and recent oral steroid use are recognised risk markers for severe exacerbation and asthma death: these patients need urgent clinical review, not further supply.1, 3 Anyone using their reliever three or more times per week, or presenting with three or more SABA inhaler prescriptions in the past year, has poorly controlled asthma requiring a full review of maintenance therapy and an updated written asthma action plan.2, 3, 4 Any patient who has no inhaled corticosteroid or preventer in their medication history should be referred for GP review: SABA monotherapy is no longer recommended.1, 4 Apply a lower threshold for urgent referral in pregnancy, as acute asthma poses risk to both mother and fetus.1 Older adults may not perceive breathlessness accurately: rely on objective markers and apply a lower threshold for escalation.
Emergency supply or PGD supply (where locally commissioned and within PGD criteria) is appropriate only for a mild exacerbation with a confirmed asthma diagnosis, PEF above 75 percent of best or predicted, ability to speak in full sentences, and clear response to reliever treatment within 15 to 20 minutes.1 Advise 2 to 4 puffs of salbutamol via a spacer, repeating every 20 minutes in the first hour if needed. Check inhaler technique, confirm the patient has a functioning spacer, check that the inhaler is not expired and has doses remaining, and verify that an inhaled corticosteroid or maintenance inhaler is being taken as prescribed. Do not supply a reliever as isolated treatment where the patient has no inhaled corticosteroid or maintenance plan: SABA monotherapy is no longer recommended and this carries a documented patient safety risk.1, 4 Confirm whether the patient is on AIR or MART therapy, as supplying a traditional SABA when a combination inhaler has been prescribed may undermine their management plan. Ask about annual reliever use: three or more prescriptions in the past year, or any escalating pattern, indicates poor control and warrants GP review rather than further supply.2, 3, 4 Confirm whether the patient has a written asthma action plan and flag its absence to their GP. Do not make repeated supplies without direct GP contact and documented follow-up. Document the supply, the clinical assessment, and all advice given. Provide explicit safety netting: call 999 if breathing worsens, the patient becomes drowsy or unable to speak, or lips or fingertips turn blue. Seek urgent same-day clinical assessment if symptoms do not clearly improve after initial reliever treatment, if reliever is needed repeatedly, or if symptoms return soon after treatment. All children with acute wheeze presenting at the pharmacy counter require confirmation of a parent-held written asthma action plan and a low threshold for same-day clinical assessment: do not manage via self-care. Any child with poor response to reliever, severe features, SpO2 concern, or inability to speak, feed, or play normally requires 999 or emergency assessment.
Key takeaways
- A silent chest, SpO2 below 92 percent, or no response to 10 puffs of salbutamol are life-threatening features: call 999 immediately. Do not allow the patient to travel alone or drive themselves.1
- Acute severe asthma (PEF 33 to 50 percent, unable to complete sentences, respiratory rate 25 or above, pulse 110 or above) requires emergency hospital assessment: call 999 from a community pharmacy unless an immediately safe local transfer pathway exists. A normal SpO2 does not exclude acute severe asthma.1
- Three or more SABA inhaler prescriptions per year indicates overuse and increased risk of severe exacerbations and mortality. SABA monotherapy is no longer recommended: any patient without an inhaled corticosteroid or preventer in their regimen requires GP referral, not further supply.1, 3, 4
📚 References
- National Institute for Health and Care Excellence, British Thoracic Society, and Scottish Intercollegiate Guidelines Network. Asthma: diagnosis, monitoring and chronic asthma management (NICE NG245). London: NICE; 2024 Nov. Available at: nice.org.uk/guidance/ng245
- National Institute for Health and Care Excellence. Asthma: Clinical Knowledge Summary. London: NICE; 2024. Available at: cks.nice.org.uk/topics/asthma/
- Medicines and Healthcare products Regulatory Agency. MHRA Drug Safety Update: Overuse of short-acting beta-agonist inhalers in asthma. London: MHRA; 2019 Oct;13(3). Available at: gov.uk/drug-safety-update/short-acting-beta-agonist-inhalers-overuse-in-asthma
- Medicines and Healthcare products Regulatory Agency. MHRA Drug Safety Update: Short-acting beta 2 agonists (SABA): reminder of the risks from overuse in asthma and to be aware of changes in the SABA prescribing guidelines. London: MHRA; 2025 Apr. Available at: gov.uk/drug-safety-update/short-acting-beta-2-agonists-saba-salbutamol-and-terbutaline-reminder-of-the-risks-from-overuse-in-asthma-and-to-be-aware-of-changes-in-the-saba-prescribing-guidelines