ABSTRACT
Objective:To investigate the pharmacokinetics of sugammadex in reversal of postoperative residual neuromuscular blockade in obese patients.Methods:Sixteen patients of both sexes, aged 18-65 yr, of American Society of Anesthesiologists physical statusⅠ or Ⅱ, with body mass index of ≥25 kg/m 2, scheduled for elective laparoscopic bariatric surgery, were selected.The patients were divided into 2 groups ( n=8 each) according to the degree of obesity: group O (25 kg/m 2≤BMI<40 kg/m 2) and group M (BMI≥40 kg/m 2). In group O and group M, vecuronium was administered by closed-loop muscle relaxant injection system to maintain moderate neuromuscular blockade.The administration was stopped at the end of surgery, and sugammadex 2 mg/kg was injected according to corrected body weight (CBW) of patients when the muscle relaxation monitoring T 2 recovered naturally.The recovery time of neuromuscular blockade and the occurrence of residual neuromuscular blockade within 3 h after surgery were recorded.Arterial blood samples were collected at 2, 3, 5, 10, 15, 20, 30, 60, 120, 240, 360 and 480 min after administration of sugammadex.The concentration of sugammadex in plasma was determined by ultra-performance liquid chromatography-mass spectrometry.The pharmacokinetic parameters were calculated with PKSolver software. Results:No residual neuromuscular blockade occurred, and the pharmacokinetics of sugammadex in plasma were consistent with the linear non-compartmental model in the two groups.Compared with group O, apparent clearance was increased ( P<0.05), and no significant change was found in other pharmacokinetic parameters, recovery time of neuromuscular blockade and concentrations of sugammadex in plasma at different time point ( P>0.05) in group M. Conclusion:The pharmacokinetics of sugammadex in reversal of postoperative residual neuromuscular blockade in obese patients are consistent with the linear non-compartmental model, and the clearance of sugammadex is higher in morbidly obese patients.