Abstract
BACKGROUND: Sugammadex, a neuromuscular blockade reversal agent, has a reported incidence of severe anaphylaxis of approximately 0.005% in Japan, typically occurring within 5 min of administration. However, detailed case reports describing the full clinical course and associated changes in monitoring parameters—such as vital signs, capnographic waveforms, and airway pressure—remain limited. CASE PRESENTATION: We report the case of an 80-year-old man who underwent laparoscopic partial hepatectomy under combined general and epidural anesthesia. Postoperatively, 200 mg of sugammadex was administered to reverse neuromuscular blockade. Within 2 min, the ventilator’s high airway pressure alarm was triggered, and capnography showed an obstructive pattern as ventilation became difficult. Suspecting a severe asthma attack, we initiated treatment with 3% sevoflurane for bronchodilation and administered 0.3 mg of intramuscular adrenaline. A full-body examination revealed a red rash on the upper abdomen and redness with edema of the eyelids, confirming an anaphylactic reaction. Sugammadex-induced anaphylaxis was diagnosed. The systolic blood pressure had transiently dropped to 71 mmHg but improved with a single 0.15 mg dose of phenylephrine. Extubation was delayed due to marked upper airway edema and an incompletely normalized capnographic pattern of obstruction; the patient was maintained on mechanical ventilation under deep sedation until safe extubation on postoperative day 1. CONCLUSIONS: Sugammadex-induced anaphylaxis can occur rapidly following administration. This case highlights the value of continuous electronic monitoring, which enabled documentation of detailed real-time changes in vital signs, capnography, and airway pressure from the onset of bronchospasm to recovery. Given persistent bronchospasm despite adequate oxygenation, mechanical ventilation was continued with the patient intubated and sedated. Such comprehensive monitoring data provide important insights for the early recognition and management of intraoperative anaphylaxis.