perioperative anaphylaxis

1. PERIOPERATIVE ANAPHYLAXIS
DR GEETANJALI S VERMA
CONSULTANT, ANAESTHETICS
CUMBERLAND INFIRMARY

2. TOPICS COVERED
• Introduction/ epidemiology
• Pathophysiology
• Causes
• Detection
• Management
• Reporting/ follow up
• Future anaesthetics

3. INTRODUCTION
• Perioperative anaphylaxis is a life-threatening immediate
hypersensitivity condition that is usually IgE mediated. Occurs rarely,
but may lead to morbidity or mortality.
• Perioperative anaphylaxis in children: 1 in 10,000
• 6th UK National Audit Project (NAP6): overall incidence 1 in 11,752.
• Mortality rate with perioperative anaphylaxis: 4% in France; 3.8% in
UK, 0 deaths in Western Australia.
• Morbidity rate unknown.

4. PATHOPHYISOLOGY

5. CAUSES (NAP6)
1. Antibiotics – 48% (co amox, teic = 90%)
2. NMR – 25% (Sch>vec/roc>atrac)
3. Colloids (gelatin)
4. Induction agents (thio 1:14000)
5. Others:
• contrast (patent blue, methylene blue)
• Drugs: protamine, atropine, morphine
• bone cement
• Chlorhexidine 9%
• Latex : 0 cases in NAP6

6. CLINICAL FEATURES
Features
Proportion of patients (%)
No pulse detected, hypotension 28
Difficulty inflating lungs 26
Flushing 21
Coughing 6
Rash 4
Desaturation 3
Cyanosis 3
Other—ECG change, wheeze, urticaria 9
Usually within minutes of induction

7. Grading
Clinical presentations of perioperative immediate hypersensitivity based on the Ring and Messmer four-step (I–
IV) grading scale
Grade Clinical signs
I Mucocutaneous signs: generalised erythema, extensive
urticaria with or without angioedema
II Moderate multivisceral signs: mucocutaneous signs,
moderate hypotension, tachycardia, or both with or
without moderate bronchospasm or gastrointestinal
symptoms
III Life-threatening mono- or multivisceral signs: life-
threatening hypotension, tachycardia or bradycardia
with or without cardiac arrhythmia, mucocutaneous
signs, severe bronchospasm or gastrointestinal
symptoms
The cutaneous features may be absent before the
restoration of haemodynamic stability
IV Cardiac arrest

8. MANAGEMENT

10. ANAPHYLAXIS DRILL
Immediate management
Stop the administration of all agents likely to have caused the anaphylaxis.
Call for help.
Maintain the airway, give oxygen 100% and lie the patient flat with the legs elevated.
Give epinephrine. 0.5–1 mg IM (0.5–1 ml of 1:1000); may be repeated every 10 min according to the arterial pressure and pulse until
improvement occurs.
Alternatively, 50–100 µg IV (0.5–1 ml of 1:10 000) over 1 min has been recommended for patients with cardiovascular collapse, with
titration of further doses as required. This should be given at a rate of 0.1 mg min−1 stopping when a response has been obtained.
It is important that undiluted epinephrine 1:1000 is never given i.v.
Give i.v. fluid with colloid or crystalloid (avoiding colloids that have a higher incidence of allergy). Adult patients may require 2–4 litre.
Subsequent management
Give antihistamines (chlorpheniramine 10–20 mg by slow i.v. infusion)
Give corticosteroids (100–500 mg hydrocortisone slowly i.v.).
Bronchodilators may be required for persistent bronchospasm.
Catecholamine infusion as CVS instability may last several hours.
Epinephrine 0.05–0.1 mg kg−1 min−1 (4 ml h−1 of 1:10 000 for 70 kg adult).
Check ABGs for acidosis and consider bicarbonate 0.5–1.0 mmol kg−1 (8.4% solution = 1 mmol ml−1).

11. Other drugs?
• Antihistamines and steroids
• No evidence for the use of H1-, H2-, or both antihistamines, steroids,
or both in acute anaphylaxis.
• H1-antihistamines are useful for the symptomatic treatment of
urticaria, angioedema, and pruritus in awake patients.1

12. Proceed / abandon surgery?
• No defined criteria regarding the decision
• To be evaluated on a case-by-case basis taking into consideration the
urgency of surgery, severity of reaction, response to treatment, and
underlying comorbidities.
• Study: no difference in major hypersensitivity-related complications
found for cases with Grade III reactions, whether surgery had been
abandoned or continued, once resuscitation had been achieved.
• Surgery was frequently postponed in Grade IV reactions, which were
associated with a high rate of complications

13. Reporting / follow up
• Risk register reporting – local guidelines
• All suspected anaphylactic reactions should be reported on a ‘Yellow Card’
• The patient should be informed of the perioperative event and given a
referral for follow-up.
• Written information with detailed information about drug exposures to be
avoided until investigations have been performed should be provided.
• In the UK, it is the responsibility of the anaesthetist to refer the patient to
the allergy clinic.
• The patient should be given a written record of the reaction and be
encouraged to carry an anaesthetic hazard card or Medic-Alert bracelet

14. Tests
1. Histamine and tryptase measurements
• Histamine is a preformed mediator produced by basophils and mast cells, which is measured in
the plasma (N<10 nmol L−1).
• The peak is immediate and the elimination half-life is 15–20 min.
• Histamine concentrations are preferably measured within 30 min after anaphylaxis onset, and up
to 1–2 h after, if not done earlier.
• Tryptase is a neutral serine protease contained predominantly within mast cells.
• Total tryptase concentration is measured in the plasma or serum (N<11–13 μg L−1).
• It reaches a peak between 15 min and 2 h after anaphylaxis onset; the elimination half-life is
around 90–120 min.
• Samples sent at 0,6,12-24hrs
• level above 1.2×baseline+2 μg L−1 is considered to be indicative of mast cell activation.
2. SKIN TESTING
3. SERUM IgE measurement
4. Basophil activation test

15. Previous anaphylaxis
• Identify causative agent
• RA>GA (inhalational>IV)
• Premedication in GA: hydrocort/ ranitidine/ salbutamol
• Full monitoring before start of anaesthesia; IV access (18G/>)
• Pre oxygenation
• Emergency drugs/ anaphylaxis kit – immediate availability