Anaphylaxis
Suspect anaphylaxis when one or more of: unexplained hypotension; unexplained bronchospasm (wheeze may be absent if severe); unexplained tachycardia or bradycardia; angioedema (often absent in severe cases); unexpected cardiac arrest where other causes are excluded; cutaneous flushing in association with one or more of the signs above (often absent in severe cases).
Adult adrenaline:
i.v. 50 µg (= 0.5 ml of 1:10 000)
i.m. 0.5 mg (= 0.5 ml of 1:1000) if i.v. not possible
Paediatric adrenaline:
i.v. 1.0 µg.kg⁻¹ (0.1 ml.kg⁻¹ of 1:100 000)
[1:100 000 solution made by diluting 1 ml of 1:10 000 up to 10 ml]
If no i.v. access, intraosseous adrenaline dose same as i.v.
Suggested adrenaline infusion regimes (adult):
5 mg in 500 ml dextrose = 1:100 000, titrate to effect
3 mg in 50 ml saline. Start at 3 ml.h⁻¹ (= 3 µg.min⁻¹), titrate to maximum 40 ml.h⁻¹ (= 40 µg.min⁻¹)
Glucagon (adult): 1 mg, repeat as necessary
Vasopressin (adult): 2 units, repeat as necessary (consider infusion)
CARDIAC ARREST → 2-1
AFTER initial resuscitation:
Consider steroids for refractory reactions or ongoing asthma/shock.
Antihistamines (preferably oral, non-sedating) can be given for skin symptoms.
Repeat testing for serum tryptase at 1–2 hours and >24 hours.
Liaise with hospital laboratory about analysis of samples.
Liaise with department anaphylaxis lead regarding referral to a specialist allergy or immunology centre to identify the causative agent (see www.bsaci.org for details).
Inform the patient, surgeon and general practitioner.
Report to MHRA (https://yellowcard.mhra.gov.uk).
NAP6 online resource including anaphylaxis follow-up packs: http://www.nationalauditprojects.org.uk/NAP6-Resources#pt