title: [Pharmacokinetics of a cisatracurium dose according to fat-free mass for anesthesia induction in morbidly obese patients].
abstract: OBJECTIVE
  To compare the pharmacokinetics of cisatracurium between normal weight patients and morbidly obese patients.
  
  
  METHODS
  Twelve obese ASA I-II patients (BMI≥35 kg/m2) undergoing laparoscopic Roux-en-Y gastric bypass and 12 normal weight ASA I-II patients (BMI of 18.5-24 kg/m2) undergoing laparoscopic surgery were enrolled. The obese patients were given a cisatracurium dose of 0.15 mg/kg according to the fat-free mass (FFM), and the non-obese patients received a dose of 0.15 mg/kg according to the total body weight. Plasma concentrations of cisatracurium was monitored in the patients with high-performance liquid chromatography (HPLC) before anesthetic induction and at 1, 2, 4, 6, 8, 10, 12, 15, and 20 min after cisatracurium administration and the pharmacokinetic parameters were computed. SBP, DBP, HR, MAP, SpO2and PetCO2were recorded before anesthetic induction (T0) and at 1 min (T1), 2 min (T2), 4 min (T3) after cisatracurium administration.
  
  
  RESULTS
  Compared with those measured at T0, SBP, DBP and MAP in the 2 groups were significantly decreased at the time points of T1-3(P<0.05). Compared with the non-obese patients, the obese patients showed significantly increased Hct level (P<0.05). The total clearance, apparent volume of distribution, and distribution and elimination half-life of the drug were similar between the 2 groups (P>0.05). The plasma concentration of cisatracurium at T1-2was significantly decreased in the obese patients compared with that in the non-obese patients (P<0.05).
  
  
  CONCLUSIONS
  Cisatracurium doses according to fat-free mass is clinically reasonable for inducing anesthesia in morbidly obese patients, but due to a prolonged muscle relax onset time, the timing of tracheal intubation should be delayed by 1-2 min.
authors: Department of Anesthesiology, First Affiliated Hospital of Jinan University, Guangzhou 510630, China. E-mail: 564676251@qq.com.
authors: Jia-Yang
authors: JY
authors: Li
authors: Qi-Rong
authors: QR
authors: Zou
authors: Xue-Mei
authors: XM
authors: Peng
mesh_terms: D000758:Anesthesia; D001279:Atracurium / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D015390:Gastric Bypass; D006207:Half-Life; D006801:Humans; D010535:Laparoscopy; D009767:Obesity, Morbid / Q000097:blood*; D013997:Time Factors
chemical_list: D001279:Atracurium; C101584:cisatracurium