We offer an allergy testing service for patients who have suffered a suspected allergic reaction to drugs administered during an anaesthetic.  Patients are usually referred to us by the anaesthetist concerned, although if you have concerns that you have suffered an allergic reaction, particularly an anaphylactic reaction, and have not been investigated please feel free to contact us.  Dr Harding is a member of the Australian and New Zealand Anaesthetic Allergy Group (AANZAG), which is a group of anaesthetists, allergists, immunologists, scientists, and others with an interest in allergies to anaesthetic drugs.  ANZAAG members provide specialist advice to other clinicians and to the Australian and New Zealand College of Anaesthetists, the peak body for anaesthesia in Australia and New Zealand.

Testing takes place after a consultation in our rooms.  During this consultation we will enquire about details of any known allergies, any previous anaesthetics, and exposure to a number of possible agents that may sensitise you to some anaesthetic drugs.  We will also explain the testing process and usually arrange for you to have some blood tests prior to your testing.  We will get you to sign a consent form for the testing procedure and for us to photograph your test results.  We retain a copy of the photographs for our own records, include them in the medical record at the hospital you are tested at, as well as including them in the letters we provide, you, the referring anaesthetist, and your GP.

It is best to be tested four to six weeks after any major reaction.  Our staff will arrange a suitable day for you to be tested.  The tests themselves are conducted as a day stay procedure at St John of God Bendigo and usually take 3 to 4 hours to complete.  The actual testing involves a large number of injections in your forearm, which are observed for any sign of a reaction.  You will be tested for all the drugs used in your anaesthetic, and a wide range of similar drugs.  This ensures that drugs that might also cause a reaction are tested, and to also test alternative drugs that can be used in future anaesthetics.  A positive test is indicated by a red swelling at the site of injection.  It is extremely rare (but not impossible) for you to have a serious reaction to the drugs during testing.  It is also possible for there to be false positives and false negatives.  On the day of your testing we will tell you what we think the results mean and we will provide you with a letter detailing your test for you to keep and show any future anaesthetist.  We also write to the doctor who referred you to us, and if you are happy for us to do so we will send a copy of this letter to your General Practitioner.  If you have had a positive test we will also send you an application form for a medic alert bracelet.  We recommend that anyone who tests positive should obtain a medic alert bracelet so that in an emergency those caring for you are aware of your allergy.

For patients with private health insurance we bill both your initial consultation and the testing at your funds applicable "no gap" rate.

 

Advice for Medical Practitioners

We are happy to be consulted by other anaesthetists, including GP anaesthetists, at any time.  We are happy to provide advice on pre-operative planning, peri-operative management (including advice dealing with a crisis), and testing after a suspected event.  If anaphylaxis is suspected it is important to obtain tryptase samples.  Tryptase levels peak between 30 and 90 minutes after onset of an anaphylactic reaction.   Please endeavour to collect a peak sample in this time window, we realise this may be easily overlooked in the midst of an ongoing crisis.  If bloods are available pre operatively a retrospective level may be of assistance.  Levels fall back to baseline after 48-72 hours, a baseline sample at this time may be more useful than one at 24 hours, again we realise this may not be possible.

If you are unfortunate enough to have had a patient with a suspected case of anaphylaxis during anaesthesia please refer the patient for testing.  Please use the referral forms available on the ANZAAG website.  We realise they are involved, but they gather all the useful information required to guide testing.  Please also report the event via webAIRS.

The ANZAAG website has available the current reccomended treatment and investigation protocols on a series of cards.  These are evidence based (or based on expert consensus where evidence is scant or unclear), endorsed by the Australian and New Zealand College of Anaesthetists, and tailored specifically to anaesthesia; remember you may have just shot 2g of antigen directly into a vein and precipitated a far more significant reaction than from other exposures.  They also assist by providing a framework for decision making at a time of high stress levels and high workload.  Other guidelines in circulation do not usually cater for this scenario, and are often aimed at a different target audience.  We encourage hospitals to put together an "anaphylaxis box", including laminated versions of the cards.  Once again we are happy to provide advice on putting such kits together.

If you encounter a patient who has a letter detailing previous anaesthetic testing please either annotate the letter, or provide a further letter detailing what technique and drugs you used and the outcome.  This helps build an ongoing file for the patient, and the next anaesthetist.