Two cases of circulatory collapse due to suspected remimazolam anaphylaxis

Abstract

Background Remimazolam was approved in Japan in January 2020. We report two cases of circulatory collapse due to suspected remimazolam anaphylaxis during anesthetic induction. Case presentation Case 1: A 74-year-old male was scheduled for debridement and skin grafting for a severe burn injury. We induced anesthesia with 4 mg of remimazolam and 20 mg of ketamine. The patient subsequently developed treatment-resistant severe hypotension. Case 2: A 59-year-old male was scheduled for laparoscopic-assisted sigmoid colectomy. We induced anesthesia with 9 mg of remimazolam. Within a few minutes, the patient developed treatment-resistant severe hypotension. As serum tryptase was elevated in both cases and only intravenous administration of adrenaline was effective, we considered the circulatory collapse might be due to anaphylaxis. Conclusion We experienced two cases of circulatory collapse due to suspected remimazolam anaphylaxis during anesthetic induction. The prevalence of remimazolam anaphylaxis is not yet known, and further research is needed.

An update on remimazolam and anaphylaxis

“…8 Recently, anaphylactic issues have been reported with the use of remimazolam, 9-13 these 10 cases having been reported in Japan and South Korea. Clinical symptoms were frequently major cardiovascular events (hypotension, shock, and cardiac arrest), [9][10][11][12][13] and less frequently respiratory or cutaneous signs. 13 In all cases, the outcome was good, adequate resuscitation was provided, and epinephrine was used.…”

“…Remimazolam was officially approved as a novel anaesthetic agent in Japan in January 2020, and it then received marketing authorisation in Europe in March 2021 for the indication of procedural sedation 8 . Recently, anaphylactic issues have been reported with the use of remimazolam, 9–13 these 10 cases having been reported in Japan and South Korea. Clinical symptoms were frequently major cardiovascular events (hypotension, shock, and cardiac arrest), 9–13 and less frequently respiratory or cutaneous signs 13 .…”

Remimazolam: Is the quest for the holy grail of sedation during diagnostic or endoscopic interventions over?

“…During the production of this editorial, two further cases of suspected remimazolam anaphylaxis have been published. 18…”

“…However, it is not certain that remimazolam is the holy grail of endoscopic sedation. During the production of this editorial, two further cases of suspected remimazolam anaphylaxis have been published 18 …”

“…During the evaluation of remimazolam other additional adverse effects may arise along the way. In 2021, a patient who had previously received midazolam in association with general anaesthesia 4 weeks earlier experienced anaphylaxis shortly after receiving an induction dose of remimazolam for general anaesthesia 15 and very recently, seven similar cases of suspected anaphylaxis after remimazolam administration have been published 16,17 . Remimazolam contains dextran 40 as an additive, and this has been suspected as the underlying cause for the anaphylaxis.…”