Propofol use in children with allergies to egg, peanut, soybean or other legumes
This is a retrospective, single-centre study from Western Australia looking for incidence of propofol allergy in patients with egg, peanut, soybean and other legume allergy from a 10-year period (2005-2015) that received propofol as part of their general anaesthetic (304 children received 648 propofol exposures identified). The control group of 892 non-allergic children with 1 propofol exposure each was selected prospectively from their database of research participants.
10 patients from the study group were found to meet the criteria for a possible allergic reaction – a non-allergic explanation was deemed likely for 8 of these; 1 was thought to be provoked by combination of prior exposure to intralipid in TPN and propofol during anaesthesia causing minor peri-oral and peri-orbital swelling 2 hours after the propofol exposure; and 1 was an asthmatic patient who develop shortness of breath and desaturation to 85% on room air in the recovery area thought to be most likely due to bronchospasm and atelectasis although propofol allergy cannot be excluded. Of the control group, possible allergic reactions were identified in 124 procedures and none required follow-up for allergic symptoms. On review, these reactions were thought unlikely to be caused by propofol.
This study is the first one with a large cohort that looked at peanut and legumes in addition to egg, which are all major additives used in formation of emulsified propofol. One possible limitation of the study is lack of discussion of whether the propofol solution used in the study group is exactly same as the propofol used in the control group with regards to variation in areas such as manufacturer technique, other drug additives and evolution of industrial practice. Also, it was not clear how the control group were selected – was the whole database of non-allergic research participants included? Is this why the control group was almost 3 times the number of the study group? Nevertheless, these do not detract from the findings of the study.
Take home message:
This large study confirms the commonly held perception among anaesthetists that serious propofol allergy is rare. We now also have some evidence propofol allergy is not reliably predicted by history of food allergy.
Reviewed by: Dr K.C. Law