title: Neostigmine-induced reversal of vecuronium in normal weight, overweight and obese female patients.
abstract: BACKGROUND
  The purpose of this study was to compare neostigmine-induced reversal of vecuronium in normal weight, overweight and obese female patients.
  
  
  METHODS
  In total, 15 each of normal weight (18.5<or=BMI<25), overweight (25<or=BMI<30) and obese (BMI>or=30) patients were enrolled. Anaesthesia was induced and maintained with fentanyl, propofol and nitrous oxide. Neuromuscular block was induced with vecuronium 0.1 mg kg(-1) on the basis of the patient's real body weight (RBW) and was monitored using acceleromyographic train-of-four (TOF) of the adductor pollicis. All patients received neostigmine 0.04 mg kg(-1) combined with atropine 0.02 mg kg(-1) at 25% recovery of the first twitch (T1) of TOF and were allowed to recover to a TOF ratio of 0.9.
  
  
  RESULTS
  The time from administration of vecuronium to spontaneous recovery of T1 to 25% of control was significantly longer in the obese [mean (SD, range); 68.4 (16.3, 39.8-110.8) min] and the overweight groups [49.3 (6.2, 39.8-60.8) min] as compared with the normal weight group [41.0 (9.0, 27.5-59.5) min]. The times for facilitated recovery with neostigmine to a TOF ratio of 0.7 did not differ among groups. However, the recovery to a TOF ratio of 0.9 in the obese [25.9 (6.7, 13.5-41.0) min] and the overweight groups [14.6 (7.7, 3.3-28.5) min] were significantly longer than that in the normal weight group [6.9 (2.0, 3.0-10.7) min].
  
  
  CONCLUSIONS
  Early reversal after neostigmine is prompt; however, recovery to a TOF ratio of 0.9 is slow in overweight and obese patients when vecuronium is dosed on the basis of the patient's RBW.
authors.affiliation: Department of Anaesthesiology, Surugadai Nihon University Hospital, 1-8-13, Kanda-Surugadai, Chiyoda-Ku, Tokyo 101-8309, Japan. suzukit@cd5.so-net.ne.jp
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: G
authors.initials: G
authors.lastname: Masaki
authors.forename: S
authors.initials: S
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009388:Neostigmine / Q000627:therapeutic use*; D019148:Neuromuscular Blockade / Q000379:methods*; D003473:Neuromuscular Nondepolarizing Agents / Q000037:antagonists & inhibitors*; D009765:Obesity / Q000503:physiopathology*; D050177:Overweight / Q000502:physiology; D014673:Vecuronium Bromide / Q000037:antagonists & inhibitors*
chemical_list: D002800:Cholinesterase Inhibitors; D003473:Neuromuscular Nondepolarizing Agents; D009388:Neostigmine; D014673:Vecuronium Bromide