Pediatric Sedation Blog

A few months ago Dr. Ed Goroza asked an interesting question:

How do sedation providers approach the child with a history of anaphlyaxis to eggs when it comes to the use of propofol?

While most anesthesia texts and “experts” in the field do not think that egg-allergy is a true contraindication to the use of propofol, it still seems that many are reluctant to use it in the egg allergic patient.

Anesthesia and Analgesia

The science

Here is an exert from Anesthesia & Analgesia that highlights some of the current science surrounding the issue:

Propofol was originally formulated with the surfactant Cremophor EL, but a series of hypersensitivity reactions prompted a change in the formulation (36,71,72). Propofol (2,6-diisopropylphenol) is currently formulated in a lipid vehicle containing soybean oil, egg lecithin, and glycerol. The incidence of anaphylactic reactions with the new formulation is 1 in 60,000, although it has been reported to cause 1.2% of cases of perioperative anaphylaxis in France (73). A more recent report from the same group in France demonstrated that 2.1% of cases of intraoperative anaphylaxis are due to propofol (5). In a report of 14 patients with documented propofol allergy on first exposure, the 2 isopropyl groups of the propofol were thought to be the sensitizing epitopes (36). Isopropyl groups are present in dermatologic products and may account for anaphylactic reaction to propofol on the first exposure. In addition, there is a report of an anaphylactic reaction to propofol at the time of the third exposure to the drug (72). Phenol may have acted as an antigen and produced sensitization that led to an episode of anaphylaxis on reexposure. Most cases of drug allergy to propofol are IgE mediated, and specific IgE RIA and intradermal skin tests have been reported (36).

Propofol is formulated in a lipid emulsion containing 10% soybean oil, 2.25% glycerol, and 1.2% egg lecithin. The egg lecithin component of propofol’s lipid vehicle is a highly purified egg yolk component (74). Ovalbumin, the principal protein of eggs, is present in the egg white. Skinprick and intradermal testing with propofol and with its lipid vehicle (Intralipid) were negative in 25 patients with documented egg allergy (74). The measles-mumps-rubella vaccine does contain small amounts of egg-related antigens (ovalbumin), which are grown in cultures of chick-embryo fibroblasts. However, the measles-mumps-rubella vaccine has been given to egg-allergic children without any episodes of anaphylaxis (75). Therefore, current evidence suggests that egg-allergic patients are not more likely to develop anaphylaxis when exposed to propofol.

As is often the case, the science of medicine does not always correlate with the practice of medicine.  Dr. Goroza surveyed the SPS listserve and the results of that survey are listed below.

Dr. Goroza’s Survey

The practice

Of the 11 responders, only 3 would still give propofol & only if there was no prior reaction to the drug. The majority of the responders would not give propofol and would instead use (some would use more than one method): barbiturates (3 responses), dexmedetomidine alone (3), dexmedetomidine with ketamine (2), benzodiazepine (2), barbiturate with opioid (1) and ketamine alone(1).

It is interesting to note that there is very little  published literature describing this topic. I was able to find the two below: