Morbidly obese patients \[ body mass index (BMI) \> 40 kg/m2 \] planned to undergo open or laparoscopic surgery for weight loss will be managed with standardized general anesthesia (intravenous Propofol combined with remifentanil and muscle relaxation induced by rocuronium).
By the end of the surgery, Group A and group E patients will receive sugammadex 2 mg/kg corrected body weight \[corrected body weight(CBW)=ideal body weight(IBW) + 40%(real body weight(RBW)-ideal body weight)\] when T2 arises in adductor pollicis. Group C and group G will receive neostigmine 50μg/kg corrected body weight when T2 arises in adductor pollicis. Group B and group F patients will receive sugammadex 2 mg/kg ideal body weight when T2 arises in adductor pollicis. Group D and group H patients will receive 50μg/kg neostigmine ideal body weight.
Investigators will proceed in continuous acceleromyography monitoring of adductor pollicis and corrugator supercilii during induction of anaesthesia, surgery, recovery and in the post anaesthesia care unit, recording TOF values. Total consumption of neuromuscular blocking agent, doses of reversal agents and clinical criteria of post operation residual curarization will also be recorded.