Life-threatening allergic reactions to drugs can occur in any patient undergoing surgery and
anaesthesia. The patient perspective on these events and their implications for future surgical safety, are unknown. In parallel with this problem, an estimated 1.5 million NHS surgical patients each year carry a label of drug allergy. These problems are interdependent, since fear of genuine allergy drives the precautionary approach to allergy labelling. Most drug allergy labels are incorrect. Nevertheless, their presence leads to avoidance of important drugs in the perioperative period, the impact of which is largely unknown. A critical shortage of allergy specialists means that allergy testing is largely inaccessible. For patients labelled ‘penicillin allergic’, recent research has focussed on widening access to testing through provision by non-allergist healthcare professionals. However, the evidence supporting this approach is unreliable.
The overarching aim of my research was to understand the scale and nature of any
associations between drug allergy labels and post-operative complications, to determine
safety and effectiveness of non-allergist penicillin allergy testing in surgical patients, and to
understand patient attitudes and behaviours following a suspected perioperative allergic
reaction.
I determined that the presence of a drug allergy label was associated with a 20% increase in
the risk of post-operative complications, predominantly driven by infective complications
among patients with antimicrobial allergy labels. I also demonstrated that non-allergist
penicillin allergy testing is likely to be both clinically ineffective and unsafe. Lastly, I identified that patients who suffer suspected perioperative allergic reactions can experience life-limiting anxiety and may struggle to recall their allergy diagnosis, increasing their risk of future reactions.
Future research must focus on developing safe, effective pathways for pre-operative drug
allergy delabelling to reduce the burden of surgical complications, and improving safety of
future surgery among patients who suffer perioperative allergic reactions.
