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Refractory anaphylaxis — MRCEM SBA MCQ

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HardResuscitation and critical illnessRefractory anaphylaxisMRCEM SBA

A 46-year-old man develops wheeze and profound hypotension within minutes of receiving intravenous co-amoxiclav in the emergency department. The infusion is stopped. He has no rash or facial swelling. He takes propranolol for migraine prophylaxis. He has received oxygen, two 500 microgram intramuscular doses of adrenaline five minutes apart, and 500 mL of intravenous crystalloid. He remains conscious, with a palpable pulse, blood pressure of 74/42 mmHg, SpO₂ of 92% on high-flow oxygen and persistent wheeze. Continuous monitoring and intravenous access are established. An emergency physician experienced in administering intravenous vasopressors is at the bedside. Which treatment should be prioritised now?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: A — Prioritise an intravenous adrenaline infusion alongside further crystalloid and critical care support.

The abrupt breathing and circulation problems after intravenous antibiotic administration indicate anaphylaxis despite the absence of skin changes. Persistent wheeze and shock after two appropriate intramuscular adrenaline doses meet the UK definition of refractory anaphylaxis. The priority is a titrated intravenous adrenaline infusion administered by an experienced clinician, with further rapid crystalloid resuscitation, continuous monitoring and critical care involvement. ([elft.nhs.uk](https://www.elft.nhs.uk/sites/default/files/2023-09/emergency_treatment_of_anaphylaxis_may_2021_0.pdf?utm_source=openai)) Propranolol makes glucagon (B) attractive because beta blockade may reduce the response to adrenaline. UK guidance, however, places consideration of glucagon after an adrenaline infusion and adequate fluids if symptoms remain refractory. Further intramuscular adrenaline (C) should be given at five-minute intervals *while an infusion is being established*; it is not the preferred ongoing strategy when an experienced clinician can start the infusion. Noradrenaline (D) may be considered with expert advice for shock that remains refractory to adrenaline infusion, not instead of initiating it. Hydrocortisone (E) may be considered after initial resuscitation but must not displace adrenaline and fluids in ongoing shock. This patient requires continued resuscitation and critical care support, not routine observation. ([elft.nhs.uk](https://www.elft.nhs.uk/sites/default/files/2023-09/emergency_treatment_of_anaphylaxis_may_2021_0.pdf?utm_source=openai))

Reference: Resuscitation Council UK: Emergency treatment of anaphylaxis — sections 3.1 and 6.3–6.7 (May 2021) — https://www.elft.nhs.uk/sites/default/files/2023-09/emergency_treatment_of_anaphylaxis_may_2021_0.pdf Resuscitation Council UK: Emergency treatment of anaphylaxis — section 6.7.4 (May 2021) — https://www.elft.nhs.uk/sites/default/files/2023-09/emergency_treatment_of_anaphylaxis_may_2021_0.pdf Leicestershire Partnership NHS Trust: Anaphylaxis and Drug Allergy Policy — Appendix 2 (29 July 2025) — https://www.leicspart.nhs.uk/wp-content/uploads/2021/09/Anaphylaxis-and-Drug-Allergy-Policy-Exp-Sept-28.pdf