Anaphylaxis_Clinical_Decision_Checklist

Anaphylaxis Clinical Decision Checklist (Physician Use)

Use this to think and tick through recognition, rule-in, rule-out, and immediate decisions. When in doubt, treat with IM adrenaline early.

Safety & First Impression

• I remain with the patient; call for help early.
• I will not allow standing/walking/sitting up suddenly.
• I position safely now (flat with legs raised; semi‑recumbent if breathing difficulty; recovery position if unconscious with normal breathing; left lateral if pregnant).

Recognise Anaphylaxis

• Acute onset minutes–hours after a likely trigger.
• Airway compromise: hoarse voice/stridor/oropharyngeal–laryngeal oedema.
• Breathing compromise: dyspnoea/wheeze/tachypnoea/cyanosis/SpO₂ < 94%.
• Circulatory compromise: hypotension/shock/confusion/reduced consciousness.
• Skin/mucosal changes (urticaria, angio‑oedema) or severe GI symptoms (abdo pain, vomiting, diarrhoea) — may be absent (up to 20%).

Decision to Treat with IM Adrenaline (1 mg/ml, 1:1000)

• Life‑threatening A/B/C involvement or rapidly progressive symptoms present.
• Skin‑only symptoms absent or present but not delaying decision.
• More harm from delaying adrenaline than using it in error.
• Plan: IM adrenaline now in anterolateral mid‑thigh; repeat at 5 minutes if no improvement.

Likely Trigger & Cofactors (Document, but do not delay treatment)

• Food (children: peanuts/tree nuts/cow’s milk; adults: shellfish/stone fruits/wheat/celery) or recent drug (β‑lactams, NSAIDs, NMBAs, contrast, chlorhexidine) or insect venom (bee/wasp).
• Cofactors that lower threshold: exercise, NSAIDs, alcohol, infection, stress, sleep deprivation, menstruation, cannabis.
• FDEIA suspected (food + exertion within 4–6 h; wheat/ω‑5 gliadin; plant LTP foods).
• Idiopathic possible (up to 30%).

Severity & Risk Flags

• Teenager or >30 y adult (higher mortality risk) or severe asthma.
• Persistent hypotension/shock or severe bronchospasm/stridor.
• Requires >1 IM adrenaline dose → consider “refractory” risk and urgent transfer.
• β‑blocker use (possible poor response to adrenaline; consider glucagon in hospital).

Diagnostic Criteria (any one supports diagnosis)

• Skin/mucosa involvement plus respiratory compromise and/or hypotension.
• Two or more after likely allergen exposure: skin/mucosa, respiratory compromise, hypotension, GI symptoms.
• Isolated hypotension after known allergen exposure.

Differentials (If primarily non‑A/B/C, reconsider; do not delay adrenaline if unsure)

• Severe asthma; laryngotracheitis; foreign body; vocal cord dysfunction.
• Vasovagal syncope; MI; arrhythmia; pulmonary embolism.
• Chronic urticaria/angio‑oedema; hereditary or ACE‑inhibitor angio‑oedema.
• Toxic/other: alcohol, opiates, scombroid fish; panic/anxiety/hyperventilation.
• Endocrine/other: hypoglycaemia; carcinoid; phaeochromocytoma; thyroid crisis; systemic mastocytosis.

Immediate Support (Parallel to Adrenaline; do not delay adrenaline)

• High‑flow oxygen started; monitoring attached (SpO₂, BP, ECG).
• IV access obtained; crystalloid bolus (adult 500 ml; child 10 ml/kg) if hypotensive.
• If wheeze: salbutamol ± ipratropium via MDI+spacer or oxygen nebuliser.
• Nebulised adrenaline for upper airway oedema (adjunct; not a substitute for IM adrenaline).

Special Situations

• Pregnancy: left lateral; foetal viable + refractory maternal anaphylaxis → urgent obstetric input (possible emergency caesarean in hospital).
• Cardiorespiratory arrest: call 999; high‑quality CPR; do not interrupt for IM adrenaline.

Observation & Transfer

• All patients to hospital, even if improved after AAI.
• Observe 6–12 h; 12–24 h if circulatory collapse/severe features; consider 2 h fast‑track only in low risk with sustained response.
• Monitor for biphasic reaction (≈5%).

Post‑Event (Often completed in ED/after discharge)

• Tryptase sampling requested in ED (30 min–2 h after onset; baseline at ~24 h).
• Cause documented; trigger avoidance advice given.
• AAI prescribed (two devices) if indicated; training provided; written plan supplied.
• Indications for AAI: prior anaphylaxis to food/latex/aeroallergen; exercise‑induced anaphylaxis; anaphylaxis to trace exposures; idiopathic anaphylaxis; severe asthma + food allergy; confirmed bee/wasp venom allergy.