[ANAPHYLACTIC SHOCK DUE TO REMIFENTANIL DURING GENDER-AFFIRMING SURGERY: A CASE REPORT].

A person in their twenties, assigned male at birth and diagnosed with gender incongruence, underwent gender-affirming surgery (GAS) after starting hormone therapy. Orchiectomy, penectomy, labiaplasty and vaginoplasty were planned. The preoperative evaluation revealed no contraindications to general anesthesia. Induction was performed with sevoflurane, propofol, fentanyl, remifentanil, and rocuronium. Cefazolin was administered as a prophylactic antibiotic. After bilateral orchiectomy, the patient developed rapidly worsening urticaria, wheezing, decreased oxygen saturation and hypotension. Anaphylaxis was diagnosed, and emergency treatment stabilized respiratory and circulatory function. Because the cause was unknown, the operation was paused. The patient was moved to the intensive care unit. Symptoms resolved within hours and the patient was discharged on the second postoperative day. Subsequent allergy testing, including prick and intradermal tests for anesthetics and antibiotics, revealed a positive intradermal response to remifentanil, which identified it as the cause. After detailed counseling, the patient and their family strongly wished to complete GAS, and reoperation was performed without remifentanil. The postoperative course was uneventful.