Abstract
RATIONALE: Sugammadex is a synthetic cyclodextrin derivative that reverses the effects of nondepolarizing neuromuscular blockers through selective encapsulation. Residual neuromuscular blockade (NMB) after extubation can lead to adverse events such as hypoxia and cardiac arrest. We encountered a case of residual NMB, despite the appropriate use of NMB monitoring and sugammadex, as recommended by the American Society of Anesthesiologists. PATIENT CONCERNS: A 27-year-old female underwent balloon dilatation under general anesthesia for left bronchial stenosis after lung transplantation. Rocuronium (50 mg) was administered for intubation, with 10 mg intermittently administered to maintain a train-of-four (TOF) count of <2. At the conclusion of the procedure, sugammadex (150 mg) was administered at a TOF count of 3. The patient was extubated with a TOF ratio of 100%. Fifteen minutes after transfer to the ward and 30 minutes after sugammadex administration, the patient developed respiratory distress and erythema on her trunk and upper limbs, exhibiting possible symptoms of anaphylaxis. The emergency team administered adrenaline via intramuscular injection. Despite this, the respiratory symptoms worsened. DIAGNOSES: Difficulty in breathing was possibly due to recurrent NMB caused by residual muscle relaxants that were not fully reversed. INTERVENTIONS: The patient was reintubated and transferred to the intensive care unit. Bronchoscopy performed after reintubation did not reveal signs of anaphylactic airway swelling. OUTCOMES: The patient's respiratory condition improved, and she was extubated the following morning. After extubation, she recalled being unable to breathe or move during the follow-up bronchoscopy. Plasma histamine and serum tryptase levels were measured 2 and 24 hours after the suspected anaphylactic episode, showing no increase in the levels. LESSONS: This case highlights that neuromuscular monitoring and adherence to sugammadex dosing guidelines do not entirely eliminate the risk of recurarization, which may present with anaphylaxis-like symptoms, complicating the diagnosis.