Midazolam is a major cause of intraoperative immediate hypersensitivity reactions
Saturday, March 3, 2018
South Hall A2 (Convention Center)
Ana Carolina D'Onofrio E Silva, MD, Cristiane Fernandes Boralli, Nathalia Coelho Portilho, Laila Sabino Garro, MD, Marisa Rosimeire Ribeiro, Manoela Crespo De Magalhaes, Lucila Campos, Antonio Abilio Motta, Jorge Elias Kalil Filho, MD, PhD, Pedro Giavina-Bianchi, MD PhD FAAAAI, Marcelo V. Aun, MD

Intraoperative immediate hypersensitivity reactions (HSRs) are uncommon, but anaphylactic reactions have high morbidity and mortality. Neuromuscular blocking agents (NMBAs) and latex are considered the main agents involved. We aimed to evaluate imputed agents in immediate perioperative HSRs.


Retrospective study by analyzing the results of diagnostic tests performed from 2007 to 2017 in a tertiary outpatient clinic. Skin prick tests (SPT) and intradermal (ID) tests were performed, as well as provocation tests, both with agents described on the anesthesia report and others as therapeutic options or investigation of cross-reactivity.


A total of 386 tests were performed on 101 patients (79.8% female), aged between 12 and 75 years. Of the 101 subjects, 47.5% had tested negative or are still under investigation. We found 22/62 individuals (35.5%) with positive tests for NMBAs, and 50% had cross-reactivity with other NMBA. Latex was positive in 7 patients (5 in SPT and 2 in use tests). Both use tests resulted in anaphylaxis during the test. Opioids were positive in 10/101 tests (9.9%). Midazolam resulted positive in 10/28 (35.7%), while propofol was positive in 2/78 patients (2.6%).


Although midazolam is considered an unusual cause of immediate reactions, we found a high frequency of positive tests, comparable to NMBAs results,. There was a high frequency of cross-reactivity between NMBAs. Use tests for latex were useful, but they elicited severe systemic reactions. Investigation of intraoperative reactions should include all agents used during the procedure, but it must be performed in hospital basis under medical supervision to treat systemic reactions.