Since sugammadex has begun to be clinically used as an antagonist of nondepolarizing neuromuscular blockers, there have been many reports of its side effects, such as anaphylaxis. We read with great interest the paper titled “A suspected sugammadex-induced anaphylactic shock-A case report.” We have some concerns, which we want to discuss.

Transthoracic echocardiography was considered effective for the diagnosis and treatment in this case. Impairment of the coronary circulation can occur in cases of anaphylaxis [1,2]. In this case, rocuronium was continuously infused during anesthesia. However, the depth of the neuromuscular blockade during the operation should have been mentioned. Among the reports on maintenance of the neuromuscular blockade during surgery, some papers suggest that profound neuromuscular blockade is effective but that it is better to maintain 95–97% neuromuscular blockade [3,4]. Further, the depth of the neuromuscular blockade at the time of injecting 200 mg of sugammadex should have been mentioned. In addition, 200 mg of sugammadex was administered at a dose of 3.257 mg/kg in this patient, who weighed 61.4 kg. However, a basis of determining this dose should have been provided. Furthermore, it remains unclear whether or not this dose was sufficient [3,4].

Identification of the antigen is considered an important component of patient care. Three suspicious substances, including rocuronium, sugammadex, and the rocuronium–sugammadex complex, should be selected as antigens for the skin test in cases of anaphylaxis following the administration of rocuronium and sugammadex. It will be helpful to identify the causative substances of anaphylaxis [5].