T3: Perioperative Anaphylaxis

Question 1

What is perioperative anaphylaxis?

Answer 1

It is the massive degranulation of mast cells causing the releasing of many inflammatory mediators. Mast cells are found in the skin, mucosa and other areas. There degranulation initially leads to a rapid release of inflammatory mediators. Then a delayed secretion of inflammatory cytokines.

Question 2

What causes perioperative anaphylaxis?

Answer 2

Antibiotics – the main cause

1. Teicoplanin is a relatively new antibiotic. It is the most allergenic drug (x17 times more likely to cayuse anaphylaxis than co-amoxiclav). Teicoplanin, in the UK, is the go to choice in patients with a penicillin allergy. In half the cases, it has been given on the basis of Teicoplanin. Patients who have a label with penicillin allergy get given a drug more likely to cause anaphylaxis.
2. Neuromuscular blocking agents
3. Chlorhexidine
4. Patent blue dye (sued in breast cancer surgery)

Question 3

How do we treat perioperative anaphylaxis?

Answer 3

Treatment of perioperative anaphylaxis

Adrenaline and fluids (in any setting, this is the core). Fluids are needed with the increased vascular permeability that histamine causes, blood pressure decreases. You can often need a huge amount of fluid to return circulation. Adrenaline treats symptoms (increases systemic vascular tine, improve vascular spasm and increases cardiac tone) and stops onward mast cell degranulation through beta receptors on the mast cells. If this doesn’t work give more.
If this does not work, very far down the list, vasopressin and glucagon are considered. These are last line treatments. These are used commonly in wards and clinic.