Anaphylaxis during anesthesia in Norway - A 6-year single-center follow-up study

Background: Several studies have recognized neuromuscular blocking agents as the most common cause of anaphylaxis during general anesthesia, but the reported frequencies vary considerably between countries. In Norway, the issue has raised special concern because of reports from the Norwegian Medicines Agency that suggest a high prevalence. This article presents the results from a standardized allergy follow-up examination of 83 anaphylactic reactions related to general anesthesia performed at one allergy center in Bergen, Norway. Methods: Eighty-three cases were examined during the 6 yr period of 1996-2001. The diagnostic protocol consisted of case history, serum tryptase measurements, specific immunoassays, and skin tests. Results: Immunoglobulin E-mediated anaphylaxis was established in 71.1% of the cases, and neuromuscular blocking agents were by far the most frequent allergen (93.2%). Suxamethonium was the most frequently involved substance, followed by rocuronium and vecuronium. The few reactions in which other allergies could be detected were mainly linked to latex (3.6%). Conclusions: Neuronmuscular blocking agents were the dominating antigens causing immunoglobulin E-mediated anaphylaxis in this study. The data could not be used for estimation of the incidence of allergy toward neuromuscular blocking agents in Norway. Larger patient samples, standardization of reporting, and diagnostic protocols should be pursued by network formation to produce data more suitable for epidemiologic research.