Supplementary Material for: Exploring the Landscape of Perioperative Immediate Hypersensitivity: A Comprehensive 6-Year Monocentric Observational Analysis on Epidemiology and Risk Factors

Introduction: Perioperative immediate hypersensitivity (POH) is a rare complication estimated at 1/10,000 anaesthesia. The objective of our study was to investigate the risk factors of POH over a six-year period in a French teaching hospital. Materials and methods: Single-center retrospective descriptive epidemiological study of patients treated in the operating room from January 2016 to December 2021 with and without POH. Results: 111 POH were identified out of 47,585 surgeries, mainly women (71%) with a history of asthma (16% vs 6%, p<0.001) undergoing plastic surgery (49% vs 32%, p<0.001). POH patients were more likely to receive neuromuscular blocking agents and antibiotics (respectively 88% vs 59%, p<0.001 and 59% vs 24%, p<0.001). 92% of patients underwent intraoperative sampling, only 31% benefited from an allergy consultation. 14% had positive skin test (ST). The culprit agent were neuromuscular blocking agents (47% of which 57% rocuronium, 29% suxamethonium, and 14% atracurium), antibiotics (33%, of which 80% cefazolin and 20% cefoxitin) and gelatin (7%). Conclusion: Our study reported a POH incidence of 23/10,000 anaesthesia, with identified allergens aligning with existing literature. These findings underscore the critical need for enhanced patient follow-up to monitor potential hypersensitivity and mitigate future risks.