Sugammadex hypersensitivity: a multicentre retrospective analysis of a large Australian cohort.

BACKGROUND Sugammadex hypersensitivity is an emerging safety concern. We aimed to describe the clinical and diagnostic features of perioperative hypersensitivity to sugammadex, and secondarily to provide an estimate of perioperative sugammadex hypersensitivity incidence in Australia. METHODS We retrospectively analysed cases of hypersensitivity to sugammadex diagnosed by positive intradermal or skin prick testing at six perioperative allergy clinics in Australia. We included all grades of hypersensitivity and compared life-threatening with non-life-threatening presentations. Incidence of hypersensitivity events was estimated relative to the estimated number of sugammadex administrations across two health services between January 1, 2010 and June 30, 2023. RESULTS Thirty cases were included (15 life-threatening and 15 non-life-threatening). The most common clinical signs were hypotension (n=25, 83.3%) and flushing/erythema (n=21, 70%). The median time to recognition of hypersensitivity was 5 (interquartile range 2-7.5) min. Five cases were recognised 10-30 min after administration. Serum tryptase was measured in 28 (93.3%) patients. Tryptase was positive in 15 (100%) life-threatening cases and nine (69.2%) non-life-threatening cases. The estimated incidence of sugammadex hypersensitivity was 0.004% (95% confidence interval 0.002-0.008%). CONCLUSIONS Sugammadex hypersensitivity presents similarly to other causes of perioperative hypersensitivity, however recognition can be delayed. The combination of positive serum tryptase and positive skin tests suggests an IgE-mediated mechanism of hypersensitivity. The estimated incidence of sugammadex hypersensitivity in Australia is lower than earlier reports.