Suspected perioperative anaphylaxis
Unexpected hypotension, bronchospasm, hard ventilation or skin signs during anaesthesia or surgery. Doses below are for adults (12 years and over).
All Pathways
AnesthesiologyEmergency
Perioperative Anaphylaxis Management (ANZAAG-ANZCA 2022)
Perioperative Anaphylaxis Management (ANZAAG-ANZCA 2022): Suspected perioperative anaphylaxis → Child under 12 years: use ANZAAG paediatric cards, not t...
Pathway Overview
18 steps
Algorithm Steps
18 total
01Start 02Warning Child under 12 years: use ANZAAG paediatric cards, not the adult doses below
Paediatric doses differ. Use ANZAAG-ANZCA Card 2 (immediate) and Card 4 (refractory).
- IM adrenaline 1 mg/mL (1:1,000), lateral thigh, every 5 min as needed: under 6 years 150 microg (0.15 mL); 6-12 years 300 microg (0.3 mL). Infant under 7.5 kg: 10 microg/kg (0.01 mL/kg)
- IV adrenaline bolus, infusion and fluids are weight-based: use ANZAAG-ANZCA Card 2
- Refractory: use Card 4 and contact the local or regional paediatric service
03Action Recognise anaphylaxis: skin signs may be absent
Suspect anaphylaxis with unexplained hypotension or bronchospasm, with or without skin signs.
- Hypotension or tachycardia alone, if unexpected or not responding to vasopressors; bradycardia can occur
- Bronchospasm or hard ventilation can be the only sign
- Skin signs may appear only after circulation is restored
- Beta-blockers can mask tachycardia
- Common triggers: neuromuscular blockers, antibiotics, chlorhexidine, patent blue dye, latex, synthetic colloid
04Action Remove likely triggers and stop the procedure
Do this at the same time as the next steps. Do not delay adrenaline.
- Stop any infusion that may be the trigger (for example antibiotic, synthetic colloid)
- Remove chlorhexidine: skin prep, gels, chlorhexidine-coated lines
- Remove latex from the operating room
- Stop surgery if possible; use minimal volatile or TIVA
- Record the time of onset and all drugs given
05Action Call for help and the anaphylaxis box
Organise the team.
- Assign a leader and a scribe
- Assign a reader of the ANZAAG cards
- Assign one person to prepare adrenaline
- Get large-bore IV access
06Decision Cardiac arrest or systolic BP below 50 mmHg?
In the anaesthetised patient, start chest compressions when systolic BP is below 50 mmHg.
- If Yes
07Warning Arrest or systolic BP <50 mmHg: start CPR now
Adult. PEA is the usual rhythm; VF or VT: follow ALS guidelines. Pregnant: manual left uterine displacement. After ROSC: go to the refractory step.
- Adrenaline 1 mg IV (10 mL of 0.1 mg/mL) every 1-2 min as needed (PEA)
- Elevate legs; give 2 L crystalloid rapidly
- Pregnant: caesarean delivery within 5 min if arrest or peri-arrest
08Action Refractory hypotension or ROSC: start/keep adrenaline infusion, add vasopressor
Adult. Call more help. Recheck that triggers are removed. Review the diagnosis (ANZAAG differential diagnosis card). Bronchospasm persists: see the next step.
- Adrenaline infusion (start if not running): 3 mg in 50 mL saline (60 microg/mL), 3-40 microg/min
- Add noradrenaline infusion 3-40 microg/min and/or vasopressin 1-2 units IV, then 2 units/h
- On a beta-blocker: glucagon 1-2 mg IV every 5 min until response
- Hypotension: additional crystalloid bolus 50 mL/kg. Too much adrenaline with too little fluid can cause LV outflow obstruction: check filling with echo
- If noradrenaline and vasopressin are unavailable: metaraminol or phenylephrine infusion
- Arterial line; TOE or TTE; consider CVC
- Pregnant: manual left uterine displacement; caesarean within 5 min if arrest or peri-arrest
- Cardiac bypass or ECMO if available
09Action Refractory bronchospasm: exclude other causes, add salbutamol and magnesium
Adult. Only if bronchospasm persists despite adrenaline. Keep the adrenaline infusion running.
- Exclude oesophageal intubation, circuit or airway device fault, tension pneumothorax
- Salbutamol: 12 puffs (1200 microg) by MDI, or 100-200 microg IV bolus then 5-25 microg/min
- Magnesium 2 g (8 mmol) IV over 20 min
- Consider volatile anaesthetic or ketamine
10Action Serum tryptase: at onset, 1 h, 4 h and after 24 h
Do not delay resuscitation. Use a serum (SST) or plain tube.
- First sample as soon as possible after onset
- Then at 1 h and at 4 h
- Baseline sample after 24 h
- Coagulation screen if surgery proceeds
11Action Post-crisis care once stable
Decide with the surgeon: proceed, postpone or cancel surgery.
- Moderate to life-threatening: ICU or HDU for about 24 h
- Minor or moderate that settled quickly: close monitoring for at least 6 h
- Anaphylaxis can persist for more than 24 h
- Consider a steroid once stable (secondary treatment only): dose per ANZAAG-ANZCA Card 6
- Oral non-sedating antihistamine for skin symptoms; IV or IM antihistamines not recommended
- Give the patient a letter: reaction and all agents given
- Refer for anaesthetic allergy testing (ANZAAG testing centres)
12Outcome Stable: letter given and allergy referral made
Record all drugs and times in the notes.
If No13Decision Skin signs only: no airway swelling, hypotension or bronchospasm?
Grade 1: skin signs or peripheral swelling only. Swelling of tongue or throat, stridor or hoarse voice is not Grade 1: treat as moderate or life-threatening. Grade 2 (moderate): hypotension or bronchospasm, usually with skin signs. Grade 3 (life-threatening): severe hypotension or severe bronchospasm.
- If Yes
- Yes: Grade 1
14Action Grade 1 (skin or peripheral swelling only): no adrenaline yet; watch closely
Grade 1 reactions do not usually need adrenaline. Watch for progression.
- If airway swelling, stridor, hypotension or bronchospasm develops: give IV adrenaline as for moderate (Grade 2) below
- Oral non-sedating antihistamine for urticaria or itch, when able to swallow
- IV or IM antihistamines: not recommended
- Decide with the surgeon: proceed, postpone or cancel
- Path rejoins step 10Shared downstream outcome
If No- No: Grade 2 or 3
15Action Moderate or life-threatening: airway and 100% oxygen
Check and secure the airway at the same time as the next step. Do not delay adrenaline.
- Check capnography: no trace = wrong place
- Confirm FiO2 100%
- Airway oedema: intubate early
- Bronchospasm: give IV adrenaline (next step); see refractory bronchospasm step if it persists
16Action Moderate or life-threatening: IV adrenaline bolus now
Adult. Dilute 1 mg in 10 mL = 100 microg/mL (0.1 mg/mL). Give every 1-2 min as needed. Titrate to blood pressure and airway response.
- Moderate (Grade 2): 10-20 microg IV (0.1-0.2 mL); no response: 50 microg (0.5 mL)
- Life-threatening (Grade 3): 50-100 microg IV (0.5-1 mL); no response: 200 microg (2 mL)
- No IV access or monitoring, or awaiting infusion: 500 microg IM (0.5 mL of 1 mg/mL), lateral thigh, every 5 min as needed
- After 3 boluses (IV or IM): start adrenaline infusion
- Infusion: 3 mg in 50 mL saline (60 microg/mL); start 3 mL/h (3 microg/min); titrate to max 40 mL/h (40 microg/min); can run peripherally
- Narrow margin: check the concentration and dose before each bolus
17Action Hypotension: rapid crystalloid bolus
Adult. Elevate legs. Return to supine when possible. Pregnant: manual left uterine displacement.
- Moderate: 500 mL crystalloid; life-threatening: 1000 mL; repeat as needed
- Plan for large volumes; warm fluids if possible
- Do not use synthetic colloid (possible trigger)
18Decision Not responding to adrenaline and fluids?
Hypotension or bronchospasm persists despite adrenaline and fluid boluses. Yes: go to the refractory hypotension and refractory bronchospasm steps. No: go to serum tryptase and post-crisis care.
- If Yes
- Path rejoins step 08Shared downstream outcome
If No- Path rejoins step 10Shared downstream outcome
Guideline Source
ANZAAG-ANZCA Perioperative Anaphylaxis Management Guideline (Nov 2022) and management cards
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Doses are for adults (12 years and over); for children use ANZAAG-ANZCA paediatric cards 2 and 4
- Covers anaphylaxis under anaesthetic monitoring only; outside theatre use ASCIA acute anaphylaxis guidance
- Skin signs may be absent; hypotension or bronchospasm can be the only sign
- Does not cover allergy testing details after referral
Applicable Regions
AUNZUKEUUSglobal
AU: ANZAAG-ANZCA perioperative anaphylaxis management guideline and cards (Nov 2022).
NZ: ANZAAG-ANZCA perioperative anaphylaxis management guideline and cards (Nov 2022).
UK: NAP6 (2018) findings underpin the SBP <50 mmHg CPR threshold; local UK perioperative anaphylaxis guidance may differ in dose detail.
US: Principles match international (ISPAR) consensus; check local drug concentrations.
Version 2Next review: 2027-09-30
Next steps
Finish the workflow by opening the most relevant calculator, then convert the session into a live account when you are ready.
Related Resources
Frequently Asked Questions
What is the Perioperative Anaphylaxis Management (ANZAAG-ANZCA 2022)?
The Perioperative Anaphylaxis Management (ANZAAG-ANZCA 2022) is a emergency clinical algorithm for Anesthesiology. It provides a structured decision tree to guide clinical decision-making, based on ANZAAG-ANZCA Perioperative Anaphylaxis Management Guideline (Nov 2022) and management cards.
What guideline is the Perioperative Anaphylaxis Management (ANZAAG-ANZCA 2022) based on?
This algorithm is based on ANZAAG-ANZCA Perioperative Anaphylaxis Management Guideline (Nov 2022) and management cards.
What are the limitations of the Perioperative Anaphylaxis Management (ANZAAG-ANZCA 2022)?
Known limitations include: Doses are for adults (12 years and over); for children use ANZAAG-ANZCA paediatric cards 2 and 4; Covers anaphylaxis under anaesthetic monitoring only; outside theatre use ASCIA acute anaphylaxis guidance; Skin signs may be absent; hypotension or bronchospasm can be the only sign; Does not cover allergy testing details after referral. Individual patient factors may require deviation from these recommendations.
Get AI-Powered Analysis Alongside This Algorithm
In AttendMe.ai, the Perioperative Anaphylaxis Management (ANZAAG-ANZCA 2022) appears automatically when your clinical question matches — alongside evidence from 3M+ peer-reviewed articles.
Try AttendMe Free