Novel mechanism of B cell‐mediated anaphylaxis after spinal anesthesia with bupivacaine

Dear Editor, The estimated incidence of perioperative grade 3–5 anaphylaxis is 1 per 10,000 patients administered anesthesia, with the leading causes being antibiotics, neuromuscular blocking agents, and chlorhexidine. 1 Reports on severe allergic reactions to local anesthetics are rare, 1,2 and few case reports have presented bupivacaine-induced anaphylaxis through symptomatic diagnosis and the lymphocyte stimulation test. 3 To prevent anaphylaxis recurrence, diagnostic tests should be performed for culprit drug identification, 4 including skin tests, intracutaneous tests, serum drug-specific immunoglobulin E (IgE) quantification, and basophil activation test. The Tri-Service General Hospital Institutional Review Board (TSGHIRB-A202005103) waived patient informed consent because no identifiable personal medical information of patients was obtained in this study. The initial intravenous injection of ephedrine (10 + 10 mg) and norepinephrine (incremental from 0.01 to 0.04 mg until a total of 0.1 mg) could barely maintain her systolic blood pressure to >60 mmHg in the following 20 min. Because of severe hypotension with a poor response to vasopressors, 30 mg diphenhydramine and 200 mg hydrocortisone were administered based on the high suspicion of anaphylactic shock.