This is a presentation on anaphylaxis by Michael Rose. Michael is an anaesthetist in Sydney and a leading expert in the world of anaphylaxis. He talks about the basics and recent developments in this field - an area of critical care relevant to us all.

1. Dr Michael Rose
Director, RNSH AnaestheticAllergy Service
Chair,Australian and New Zealand AnaestheticAllergy Group (ANZAAG)
Chair,ANZCA AnaestheticAllergy Subcommittee
Member,Australasian Society of Clinical Immunology and Allergy
(ASCIA)
rnsaac@gmail.com
Anaesthetic anaphylaxis
July 2013

2. Bad days don’t always come with a
warning..

3. Once upon a time….
Elective anaesthesia was dangerous…..
Death/ morbidity due to :
Older drugs
Less emphasis on surgical anaesthetic audit / CPD
Lack of patient workup/information
Poorer monitoring
Airway emergencies
Anaphylaxis
MH
Now, otherwise healthy patients “expect” to make it through
without problems

4. Anaesthetic emergencies
Now….Anaphylaxis one of the most prominent causes of
unanticipated sudden catastrophe
Incidence of :
MH: 1:50,000 -1:100,000
CICO: 1:12,500 - 1:50,000
Anaphylaxis under anaesthesia: 1: 4,500 -1:10,000

5. What is
anaphylaxis ?
Anaphylactic vs. anaphylactoid now obsolete terminology
Clinical anaphylaxis - the presence of the following
Skin or mucosal changes – rash (erythema/urticaria) , peau d’orange,
angioedema
Plus one of…
Cardiovascular instability (hypotension, variable HR changes)
Respiratory insufficiency – bronchospasm, low sats
GIT issues – pain, vomiting, diarrhoea
Sampson HA, Muñoz-Furlong A, Campbell RL, Adkinson NF et al. Second symposium on the definition and management of anaphylaxis: Summary report—Second National
Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium. J Allergy and Clin Immunol 2006 ;117(2): 391-397

6. Severity Grading
1. Cutaneous Signs
2. Moderate multi-organ involvement
Includes hypotension, severe tachycardia, bronchial hyper-
reactivity
3. Severe multi-organ involvement
Includes severe bronchospasm, arrhythmias, cardiovascular
collapse
4. Cardiac and or respiratory arrest
5. Death (bad, lots of paperwork)

7. What makes anaesthetic anaphylaxis
different from food anaphylaxis ?
 Often sudden onset and severe
IV administration of antigen generally (except chlorhex/dyes/latex)
 Often other things occurring that may mimic anaphylaxis
 Insufflation of peritoneum
 Cardiac ischaemia
 Haemorrhage
 Intubation (bronchospasm)
 Skin reaction often not seen at time or at all
 Gastrointestinal symptoms not prominent/noticed

8. As a result…
Delayed/missed diagnoses
Unnecessary investigations

9. Anaesthetists or Immunologists??
Differing experiences of anaphylaxis
Differing approaches
Collaboration useful
ANZAAG has the best of both worlds
www.anzaag.com

11. What do we do?
History:
of event from notes/anaesthetist/patient
Results of already conducted investigations (e.g. MCT, sIgE)
Skin testing
Intradermal (standard +/- stronger “validated” concentrations)
Skin Prick
Serum tests
Baseline MCT
SIgEs (“RASTs”)
Morphine/pholcodine for NMBAs
Chlorhexidine
Latex
Antibiotics
IV Challenge
The 1st
year registrar 2am test….

13. Red flags of difficult cases
Poor information / documentation
Not referred directly from the anaesthetist involved
Vague descriptions of events (mild hypotension, possible rash)
No MCTS
High normal or completely normal MCTs with a good clinical
picture
Severe atopy and dermatographism

14. Causes – RNSAAC 2007-2013
1. NMBAs
2. Antibiotics
3. Chlorhexidine
4. Colloid
5. Patent Blue
6. (Local Anaesthetics – often type 4 hypersensitivity)

15. Muscle relaxant Cross-reactivity
Probably around 60% have at least one other NMBD
cross-reacting
Some have multiple
Not entirely predicable by class/structure
Do not substitute without testing results!!

16. www.anzaag.com

21. Other ANZAAG resources

23. Mast cell tryptases
• Samples:
• First sample when situation under control (ideal 60 mins)
• 2nd sample 4 hours
• 3rd
sample 24 hours or later
• The ‘delta’ tryptase from peak to baseline often most informative
• Serum tube 5-10mls, labeled with time of sample
• Cooled to 4 degrees if delay / transport
• Post mortem samples can be useful in sudden unexplained
death

24. What’s topical
Chlorhexidine
Pholcodine
Patent Blue
When to test??????
Who should test (? all anaesthetists/intensivists)

25. Chlorhexidine
Catheter lubricant
Central lines
Mouth washes and lozenges
Skin preps
Alcohol/chlorhexidine wipes
Risk versus benefit of making them
mandatory

26. Australia
No central database, but many reports of increasing incidence
NZ
Some centres report their cases of allergy to a central body, the
Centre for Adverse Reactions Monitoring (CARM)
In the 43 years from 1965 until April 2008, CARM had 54
reports of chlorhexidine reactions.
Four years later, by April 2012, these numbers had almost
doubled to 100 reports
The Problem

27. Latex allergy –
Widespread in hospital products
Not just perioperative
Often delayed onset of reaction
Concern after reactions increased after widespread use of latex
products occurred
Less of an issue now with labeling and alternatives
Sound Familiar?

28.  Blood collectors
 Radiology procedures
 ICU
 Emergency department
 General ward staff
The solution requires…

29. A Chlorhexidine formulary list
From St George Hospital Sydney

30. 30

31. Widespread use of chlorhexidine as an antiseptic
Clearly an effective antiseptic
Broad spectrum
Persistent effect in skin
“One size fits all” approach
Controversies

32. www.chlohexidinefacts.com

33. Texas Childrens Hospital
2004 – Chlorhexidine routinely used on CVC dressing changes
2005 – Chlorhexidine mouthwashes daily for AML patients
qacA/B gene emerged in 2006
10% of MRSA 2009
22% of MRSA 2011
Resistance

34. Japan
Issued a prohibition of chlorhexidine use on mucosal
membranes in 1984
USA
FDA issued a warning about increasing incidence of allergy
from impregnated CVCs and other products in 1998
Warnings

36. Moves by health departments toward recommending
chlorhexidine for all procedures
Good evidence for effectiveness of chlorhexidine on long
duration lines (CVCs)
No good evidence of benefit for short duration peripheral access
Chlorhexidine baths pre-op?
Chlorhexidine policy

37. Chlorhexidine anaphylaxis is
increasing
Be prepared to treat
chlorhexidine allergic patients
Be extra vigilant dealing with
known chlorhexidine allergy
patients
Risk versus benefit
Still remains the most effective
antiseptic
Rethink use of chlorhexidine for
low infection risk
Develop a chlorhexidine – free

38. Case discussions
• 24yr male
• Anaphylaxis under anaesthesia for
fundoplication
• Cardiac arrest, rash, angioedema
• Treated promptly with adrenaline (bolus
and infusion) and IV fluid
• MCT 126mcg/L

39. Case 1 continued
• Skin tested -
Positive to Rocuronium
Cross reactive to
• Suxamethonium
• Cisatracurium
• Pancuronium
Negative to Vecuronium
Subsequent safe anaesthesia with
same induction drugs and
vecuronium

40. Case 2
25 year old male
Metastatic bowel cancer
Has hemicolectomy and chemotherapy to reduce peritoneal
and hepatic disease
Port inserted for chemo

41. Case 2 continued
During chemo
Multiple episodes of minor anaphylaxis from swabbing over
port site before accessing
One episode of anaphylaxis after an infusion line was swabbed
before piggy-backing a chemo solution
……….Unrecognised

42. Then…
GA for peritonectomy/liver resection
Massive anaphylaxis after a chlorhexidine coated CVC is
inserted through chlorhexidine/alcohol prep
Cardiac arrest
Resuscitated
Subsequently tested positive to chlorhexidine on
intradermal, skin prick and sIgE tests

43. Subsequently
Meeting involving theatres, radiology, ICU about how to
manage this patient and his multiple investigations without
exposure to chlorhexidine
Chlorhexidine - free protocol developed

44. Case 3
42 yr male
Percutaneous lithotripsy
Anaphylaxis post induction –
fentanyl/propofol/Keflin/clonidine/dexamethasone
Hypotension to 60mmHg plus rash
Required 500mcg total IV dose of adrenaline
Single MCT done intraoperatively (? Time)
 elevated (15.9 mcg/ml)
Postop-course complicated by bleeding. Given cephalexin as part of
treatment – caused severe red itchy rash
Intradermal testing at normal/higher concentrations negative
to all, including cephalothin

45. Case 3 cont.
Represented for testing on a second occasion.
Still negative to all tested meds
But
What if Keflin (cephalothin) was actually cephazolin??
Tested positive intradermally and SPT to cephazolin