ABSTRACT
Becker muscular dystrophy affects mainly the musculoskeletal system, causing muscle wasting and progressive weakness. A 61-year-old woman with breast cancer, who had been diagnosed with Becker muscular dystrophy 45 years earlier, was scheduled for right mastectomy. We induced general anesthesia with propofol, fentanyl, and a nondepolarizing muscle blocker (rocuronium). Neuromuscular function was monitored continuously by acceleromyographic train-of-four ratio (TOFr) (Watch-SX monitor). The block was reversed with sugammadex. After preoxygenation with fentanyl and propofol, the device was calibrated and the baseline TOFr was recorded. We injected 1 mg/kg of rocuronium and assessed TOF responses every 15 seconds. The maximum decrease in TOF response (to 0 twitches) was at 52 seconds. Tracheal intubation was uneventful. Anesthesia was maintained by intravenous infusion. The operation lasted 74 minutes. The second TOF twitch (T2) reappeared 86 minutes after the initial dose. After we injected 2 mg/kg of sugammadex, a TOFr of 0.7 was reached at 79 seconds; a TOFr of 0.9 was reached at 108 seconds and a TOFr of 1.0 at 152 seconds. No electrocardiographic or hemodynamic abnormalities occurred during sugammadex administration and there were no signs of residual neuromuscular blockade on awakening or adverse events in the following 24 hours.
