Chart — Emergency Nursing
Anaphylaxis Management Chart
Recognition criteria, severity grading, treatment sequence, epinephrine dosing by route and age, secondary medications, biphasic reaction monitoring, and discharge criteria at a glance.
Educational use only. Anaphylaxis is a medical emergency managed under provider direction and your facility’s emergency protocols; medication doses and routes come from provider orders, not this chart. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Epinephrine is ALWAYS first-line. No contraindications in anaphylaxis. Delay in epinephrine = increased mortality.
Antihistamines and steroids are adjuncts — they do NOT reverse anaphylaxis and are secondary to epinephrine.
Recognition — Signs by System
| System | Mild Signs | Severe Signs (anaphylaxis) |
|---|---|---|
| Skin / Mucosa (90% of cases) | Urticaria (hives), erythema, flushing, itching, mild angioedema (lip/tongue swelling) | Diffuse urticaria, severe angioedema involving tongue/uvula |
| Respiratory | Nasal congestion, rhinorrhea, sneezing | Hoarseness, stridor, wheeze, dyspnea, bronchospasm → respiratory failure |
| Cardiovascular | Mild tachycardia, pallor | Severe hypotension, tachycardia, syncope, cardiovascular collapse, cardiac arrest |
| GI | Nausea, cramping, vomiting | Severe vomiting, diarrhea, profound abdominal pain |
| Neurological | Anxiety, restlessness, 'sense of doom' | Altered mental status, loss of consciousness |
Important: Skin symptoms are ABSENT in up to 20% of anaphylaxis cases. Do NOT rule out anaphylaxis because skin is clear — cardiovascular collapse alone can be anaphylaxis.
Diagnostic Criteria
Anaphylaxis is likely if ANY one of these 3 clinical criteria is met:
Criteria 1 (most common):
Acute onset of SKIN or MUCOSA involvement + EITHER respiratory compromise OR cardiovascular collapse
Criteria 2:
Exposure to likely allergen + TWO OR MORE of: skin/mucosal, respiratory, cardiovascular, or persistent GI symptoms
Criteria 3:
Exposure to KNOWN allergen + reduced BP alone (systolic drop >30% from baseline, or age-based cutoff)
Treatment Sequence
Step 1: EPINEPHRINE — IMMEDIATELY
- •Epinephrine 0.3 mg (adult) or 0.15 mg (child 15–30 kg) IM into lateral thigh (vastus lateralis)
- •Concentration: 1:1,000 (1 mg/mL)
- •Repeat every 5–15 minutes if inadequate response
- •No contraindications to epinephrine in anaphylaxis
- •EpiPen delivers 0.3 mg auto-injector IM
NCLEX: ALWAYS first. IM lateral thigh — faster absorption than deltoid. 1:1,000 for IM (NOT 1:10,000 which is IV cardiac arrest dose).
Step 2: POSITION — Simultaneous
- •Supine with legs elevated (Trendelenburg) — maximizes venous return
- •Exception: respiratory distress → semi-recumbent (sit up slightly)
- •Pregnant: left lateral tilt (relieve aortocaval compression)
- •DO NOT allow patient to sit up or stand — 'empty ventricle syndrome' risk
NCLEX: Supine + legs elevated for most patients. Sitting up during anaphylaxis → fatal cardiovascular collapse risk.
Step 3: OXYGEN + AIRWAY
- •100% O₂ via non-rebreather mask at 10–15 L/min
- •Monitor SpO₂ continuously
- •Prepare for intubation — call anesthesia early if stridor or voice changes
- •Angioedema can make intubation impossible if left too long
- •Have surgical airway (cricothyrotomy) kit available for severe angioedema
NCLEX: Call for airway backup early — angioedema progresses rapidly. Intubation becomes impossible with severe swelling.
Step 4: IV ACCESS + FLUIDS
- •Two large-bore IV lines (18G or larger)
- •NS bolus: 1–2 liters IV rapidly for hypotension
- •Repeat boluses as needed — anaphylaxis causes massive fluid shifts (may need 4–6 L)
- •Vasopressors (norepinephrine) if hypotension unresponsive to fluids + epinephrine
NCLEX: IV fluids are the second most important intervention after epinephrine for cardiovascular collapse.
Step 5: SECONDARY MEDICATIONS
- •H1 antihistamine: Diphenhydramine (Benadryl) 25–50 mg IV or IM — relieves hives/itching only
- •H2 antihistamine: Famotidine 20 mg IV (ranitidine is no longer available — withdrawn from the US market in 2020) — adjunct benefit
- •Corticosteroid: Methylprednisolone 125 mg IV or Hydrocortisone 200 mg IV — may prevent biphasic reaction (onset 4–8h, not acute treatment)
- •Bronchodilator: Albuterol nebulized for persistent bronchospasm
NCLEX: Antihistamines and steroids do NOT stop anaphylaxis — epinephrine does. These are adjuncts only.
Step 6: GLUCAGON — if beta-blocker patient
- •Glucagon 1–5 mg IV over 5 minutes, then infusion 5–15 mcg/min
- •Use when: patient on beta-blockers + refractory hypotension not responding to epinephrine
- •Beta-blockers block epinephrine alpha/beta effects → glucagon acts via non-adrenergic pathway
NCLEX: Beta-blocker patient + anaphylaxis = add glucagon. Key pharmacology NCLEX question.
Epinephrine Dosing by Route
| Route | Concentration | Adult Dose | Pediatric Dose | Site | Indication |
|---|---|---|---|---|---|
| IM (preferred) | 1:1,000 (1 mg/mL) | 0.3–0.5 mg (0.3–0.5 mL) | 0.01 mg/kg max 0.5 mg | Lateral thigh (vastus lateralis) | Standard anaphylaxis treatment — first-line |
| Auto-injector (EpiPen) | 1:1,000 (pre-loaded) | EpiPen: 0.3 mg | EpiPen Jr: 0.15 mg (15–30 kg) | Outer thigh (through clothing OK) | Community use; prior to hospital arrival |
| IV (reserved for arrest/refractory) | 1:10,000 (0.1 mg/mL) | 0.1–0.5 mg slow IV push OR infusion 1–4 mcg/min | 0.01 mg/kg IV | IV line — requires cardiac monitoring | Cardiac arrest, refractory anaphylaxis with IV access, profound cardiovascular collapse |
| Nebulized (racemic epi) | 2.25% racemic epi | 0.5 mL in 3 mL NS via nebulizer | Same | Inhaled | Adjunct for upper airway edema / stridor (NOT primary anaphylaxis treatment) |
Concentration warning: IM anaphylaxis = 1:1,000 (1 mg/mL). IV cardiac arrest = 1:10,000 (0.1 mg/mL). These are 10× different — a critical safety distinction for NCLEX and clinical practice.
Biphasic Anaphylaxis — Monitoring
| Definition | Second anaphylaxis reaction occurring without further allergen exposure after apparent resolution of initial reaction |
| Timing | 8–72 hours after initial reaction (most within 8–12 hours) |
| Incidence | ~5–20% of anaphylaxis cases; higher risk with delayed epinephrine, severe initial reaction, unknown trigger |
| Severity | Can be as severe as or MORE severe than initial reaction |
| Observation period | Minimum 4–8 hours after apparent resolution. 24 hours for severe reactions or high-risk patients. |
| Discharge criteria | Symptoms resolved; stable for observation period; prescribe 2 EpiPens; anaphylaxis action plan; allergist referral; medical alert ID |
NCLEX Summary
Epinephrine FIRST — always, immediately, no exceptions in anaphylaxis.
IM lateral thigh (vastus lateralis) — faster than deltoid. IV reserved for cardiac arrest/refractory cases.
1:1,000 IM vs 1:10,000 IV — concentrations are 10× different.
Supine + legs elevated (not sitting up). Fatal "empty ventricle syndrome" if patient stands up during anaphylaxis.
Antihistamines do NOT reverse anaphylaxis — they only treat urticaria and itching.
Steroids have 4–8h onset — no acute benefit. May prevent biphasic reaction.
Beta-blocker + anaphylaxis → add glucagon.
Observe 4–8h minimum for biphasic reaction. Discharge with 2 EpiPens.
Related Resources
Standards & sources
Fact-checked Jun 20, 2026This page is written to align with Emergency Nurses Association (ENA) · AHA ACLS / PALS Guidelines · Advanced Trauma Life Support (ATLS). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →