Remimazolam anaphylaxis confirmed by serum tryptase elevation and skin test

Summary Anaphylactic reactions during the induction of general anaesthesia are rare. Anaesthetists should determine the pathogenesis of anaphylaxis in order to establish appropriate treatment and prevent recurrence. Very little clinical information has been published to date about anaphylaxis induced by the recently launched drug remimazolam. A 78‐year‐old man, scheduled for elective surgery for colon cancer, became profoundly hypotensive and hypoxic shortly following the induction of general anaesthesia with remimazolam, remifentanil and rocuronium. His physiological derangement was successfully managed with adrenaline, vasopressors and intravenous fluid resuscitation. His serum tryptase level was significantly elevated and an intradermal test with diluted remimazolam revealed a positive reaction, confirming the diagnosis of anaphylaxis. We believe this is the first case report of remimazolam‐induced anaphylactic shock diagnosed with a serum tryptase elevation and positive skin test.