Delayed recurarisation after sugammadex reversal

Editor, Residual paralysis is a postoperative complication that occurs in between 4 and 50% of patients.1,2 We read with great interest the first case report of recurarisation 20 min after reversal of rocuronium-induced neuromuscular block with sugammadex by Le Corre et al.3 We report here two clinical cases suggestive of delayed recurarisation in patients reversed with sugammadex. The first case was a 58-year-old man who was scheduled for aortofemoral bypass for infrarenal aortic aneurysm. The patient's medical conditions included hypertension, chronic renal failure [creatinine 132.6 μmol l−1 (1.5 mg dl−1)], sleep apnoea syndrome and being overweight (weight 89 kg, height 1.64 m). Pulse oximetry, electrocardiogram and invasive arterial blood pressure monitoring were applied. Anaesthesia was induced with midazolam 2 mg intravenously (i.v.), fentanyl 300 μg i.v., propofol 160 mg i.v. and rocuronium 80 mg i.v., and maintained with remifentanil 0.1 μg kg−1 min−1 i.v., sevoflurane (MAC 1) and rocuronium 0.45 mg kg−1 h−1 i.v. (total dose 260 mg i.v.). Surgery lasted 5 h. Analgesia was started at the end of the procedure with 5 mg of morphine via epidural catheter (L1-L2). Sugammadex 200 mg i.v. (2.25 mg kg−1) was administered when the patient began to breathe spontaneously. Four minutes later, end-tidal CO2 was 5.2 kPa (39 mmHg) and the patient responded to verbal commands, and so the endotracheal tube was removed. The patient was transferred to the postanaesthesia care unit (PACU). On arrival in the PACU, the patient was conscious and oriented, blood pressure was 140/70 mmHg, heart rate 70 bpm, respiratory rate 12 bpm, SpO2 100% and axillary temperature 35.6°C. Arterial blood gas showed a mixed acidosis. Epidural infusion was started with bupivacaine 0.125% and fentanyl 1 μg ml−1 at 6 ml h−1. Two hours later, the patient experienced uncoordinated muscle movements and dyspnoea with subsequent apnoea, hypertension and tachyarrhythmia. Postoperative recurarisation was suspected and so assisted ventilation was started and sugammadex 200 mg i.v. was given. The patient recovered completely within 30 s. The second case was a 77-year-old man (weight 69 kg, height 1.62 m) who was scheduled for laparoscopic total gastrectomy. The patient's medical conditions included hypertension and dyslipidaemia. Pulse oximetry, electrocardiogram and noninvasive arterial blood pressure monitoring were applied on arrival in the operating room. Anaesthesia was induced with atropine 0.6 mg i.v., midazolam 2 mg i.v., fentanyl 100 μg i.v., propofol 120 mg i.v. and rocuronium 70 mg i.v., and maintained with remifentanil 0.2 μg kg−1 min−1 i.v., desflurane (MAC 1) and rocuronium 0.5 mg kg−1 h−1 i.v. (total dose 235 mg i.v.). Surgery lasted 5 h. Analgesia was started at the end of the procedure with fentanyl 75 μg and bupivacaine 0.125% 10 ml via epidural catheter (T9-T10). Sugammadex 200 mg i.v. (3.3 mg kg−1) was administered when the patient began to breathe spontaneously. Five minutes later, end-tidal CO2 was 4.7 kPa (35 mmHg) and the patient responded to verbal command, and so the endotracheal tube was removed. The patient was transferred to the PACU. On arrival in the PACU, the patient was conscious and oriented, blood pressure was 210/80 mmHg, heart rate 100 bpm, respiratory rate 13 bpm, SpO2 100% and axillary temperature 36.6°C. Urapidil 30 mg i.v. was administered and epidural infusion was started with bupivacaine 0.125% and fentanyl 1 μg ml−1 at 5 ml h−1. An hour and a half later, the patient experienced weakness and dyspnoea, and his SpO2 had decreased to 67%. Postoperative recurarisation was suspected and so assisted ventilation was started and sugammadex 200 mg i.v. was given. The patient recovered completely within 2 min. Both patients were discharged from the PACU the day after entry without further complications. Both patients gave written informed consent for the publication of their cases. The clinical characteristics of respiratory failure and muscle weakness, in both cases, and uncoordinated muscle movements in the first patient, together with clinical reversal after sugammadex are highly suggestive of recurarisation.1,3 Unlike Le Corre et al.,3 recurarisation after sugammadex reversal in our patients was delayed. Factors that may have influenced the recurarisation in both cases are overdose of rocuronium, not monitoring the neuromuscular block, underdosage of sugammadex and, in the first case, moderate hypothermia, obesity, acidosis and renal failure.1,3 It is highly recommended to monitor the level of muscle relaxation, although Naguib et al.4 report that 19.3% of European and 9.4% of American anaesthesiologists never use neuromuscular monitoring. There is great variability in the metabolism and elimination of rocuronium, and therefore sugammadex should be dosed according to the depth of the neuromuscular blockade.1,3,5 A recent incidence of 2% of postoperative residual paralysis in PACU after sugammadex reversal has been described,2 and although sugammadex provides rapid reversal of neuromuscular block, unexpectedly long recovery times have been reported.6 Thus, the effectiveness of sugammadex-induced reversal should also be monitored. Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflict of interest: none.