O-52 Comparison of sugammadex to neostigmine reversal of neuromuscular blockade in patients with myasthenia gravis

Abstract

Introduction. Reversal of neuromuscular blockade (NMB) in patients with myasthenia gravis (MG) is important for the acceleration of their recovery and the prevention of postoperative residual weakness and NMB. The present study was designed to evaluate the rapidity of NMB reversal by sugammadex compared to neostigmine in patients with MG. Method. Forty patients with MG, 15 males aged 18-63 and 25 females aged 21-60, ASA physical status I-III, were subjected to trans-sternal thymectomy. All patients, Osserman's classification I-III and Leventhal score <10 points, were included in this randomized, prospective study after written informed consent was obtained. They all received their cholinesterase inhibitor medication until the time of the operation and were supplemented with a dose of methylprednisolone 100mg i.v. before the induction of anaesthesia. Standard monitoring was applied while induction and maintenance of anaesthesia was performed following the same anaesthetic scheme. Neuromuscular function was monitored using train-of-four ratio (TOF). The ulnar nerve was stimulated supramaximally at the wrist every 20 sec and the resulting electromyographic response was displayed. Rocuro-nium 0.6mg.kg-1 was administered and when maximal NMB was achieved (55±5sec) the trachea was intubated. No twitch responses were recorded for 55± 10min. After spontaneous recovery (TOF>90%) a second dose of rocuronium 0.15mg.kg-1 was administered resulting again in a profound block. Patients were divided randomly in two groups. When TOF∼50% NMB was reversed in group A (n=20) by sugammadex 4 mg.kg-1 while in group B (n=20) by neostigmine 2.5 mg. All patients were extu-bated when reversal of rocuronium was efficient (TOF>90%) and no signs of residual NMB were observed. Time from sug-ammadex and neostigmine administration to 90% recovery of the TOF ratio was recorded. Results. The two groups demonstrated similar demographic characteristics and none of the patients needed ventilatory assistance during the postoperative period. Both agents proved equally efficient in reversing NMB although a significant difference was recorded between the two groups. The mean time for 90% recovery of the TOF ratio after neostigmine administration was 9.7 min while that of sugammadex did not exceed 2.8 min (P<0.05). Discussion. Sugammadex seems to be superior to neostigmine as a reversal agent of rocuronium-induced intense NMB leading to a more rapid reappearance of normal muscle activity in these patients with their highly increased sensitivity to non-depolarizing neuromuscular blocking drugs [1].