title: Pharmacokinetics and pharmacodynamics of cisatracurium in patients undergoing surgery with two hemodilution methods.
abstract: OBJECTIVE
  To investigate the pharmacokinetics and pharmacodynamics of cisatracurium in patients undergoing surgery under acute normovolemic hemodilution (ANH) and acute hypervolemic hemodilution (AHH).
  
  
  METHODS
  Ninety patients with orthopedic surgery were divided into ANH, AHH and control groups, which received hemodilution by hydroxyethyl starch 130/0.4 transfusion, Voluven transfusion and regular transfusion and infusion during surgery, respectively. Each group was divided into 3 sub-groups, administrated with cisatracurium at dosage of 0.1, 0.2 and 0.3mg/kg respectively. The changes in plasma protein, pH and electrolytes from the hemodilution beginning to surgery finish were monitored. Before and after cisatracurium administration, the phamocodynamic indicators of muscle relaxant were observed, and the plasma drug concentration was measured.
  
  
  RESULTS
  After hemodilution or regular transfusion, all three groups experienced a distinct drop in total plasma protein, albumin and pH. Compared with control group, the plasma concentrations of both K+and Ca2+in ANH and AHH groups significantly dropped (P<0.05), and those in each group after administration of cisatracurium also dropped, compared with before (P<0.05). After administration with cisatracurium, the onset time of muscle relaxation in AHH group was extended notably, compared with AHH and control groups (P<0.05), with no distinct difference of residual pharmacodynamics parameters (P>0.05). In the same hemodilution or regular infusion, with increase of drug dosage, the onset time of muscle relaxation was shortened, and the period of no response to train-of-four stimulation, muscle relaxation blockade duration and action time of muscle relaxation blockade in body were extended (P<0.05).
  
  
  CONCLUSIONS
  When using cisatracurium under AHH, the dosage should be increased appropriately, while it need not be adjusted under ANH.
authors.affiliation: Department of Anesthesiology, Gongli Hospital, The Second Military Medical University, Pudong New Area, Shanghai 200135, China. Electronic address: guojrpd@163.com.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Anesthesiology, Zhejiang Tumor Hospital, Hangzhou 310022, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Department of Anesthesiology, Gongli Hospital, The Second Military Medical University, Pudong New Area, Shanghai 200135, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Anesthesiology, Yijishan Hospital of Wannan Medical College, Wuhu 241001, China.
authors.forename: Xiaoju
authors.initials: X
authors.lastname: Jin
mesh_terms: D000328:Adult; D001279:Atracurium / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D001803:Blood Transfusion; D005260:Female; D006438:Hemodilution / Q000379:methods*; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009466:Neuromuscular Blocking Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D019637:Orthopedic Procedures / Q000009:adverse effects
chemical_list: C485123:HES 130-0.4; D006895:Hydroxyethyl Starch Derivatives; D009466:Neuromuscular Blocking Agents; D001279:Atracurium; C101584:cisatracurium
keywords: Cisatracurium; Hemodilution; Pharmacodynamics; Pharmacokinetics