A case in which a capnometer was useful for diagnosing laryngospasm following administration of sugammadex

BACKGROUND: Sugammadex has been reported to cause upper-airway obstruction, such as laryngospasm or bronchospasm. These two conditions are treated using different approaches, but the differential diagnosis is difficult. CASE PRESENTATION: We describe a case in which general anesthesia was administered via endotracheal intubation, in combination with brachial-plexus block, for arthroscopic surgical treatment of a rotator-cuff tear caused by recurrent shoulder dislocation. The total dose of rocuronium administered was 90 mg, and the last dose of 10 mg was given 15 min before the end of the surgery. Sugammadex was intravenously administered at 100 mg to reverse the effect of rocuronium after the operation ended. After extubation in this case, we placed a mask firmly around the patient’s mouth, and thus, there was no air leakage around the mask. We detected upper-airway obstruction that was presumably attributable to administration of sugammadex. The end-tidal carbon dioxide (EtCO(2)) concentration was undetectable on a capnometer. Although 100% oxygen was administered at 10 L/min via a facemask, oxygen saturation (SpO(2)) decreased to approximately 70%. With suspected onset of laryngospasm, continuous positive airway pressure with 100% oxygen at 10 L/min was started at 30 cm H(2)O. The patient’s airway obstruction resolved after a short time. CONCLUSION: The use of a capnometer facilitated the diagnosis of laryngospasm and allowed us to administer appropriate treatment after administration of sugammadex.