title: Age and the neuromuscular blockading effects of cisatracurium.
abstract: OBJECTIVE
  To investigate the influence of age on the neuromuscular blocking effect of cisatracurium.
  
  
  METHODS
  90 patients with ASA I and II were assigned to the following groups according to their age: adults, children, and infants. Each group was subdivided into three subgroups according to the first dose of cisatracurium. Patients were administrated at a first dose of cisatracurium randomly, and their responses to train-of-four (TOF) stimulation were observed. When the same degree of the first response (T1) continuously repeats three times, the percentage of T1 inhibition was recorded, and the curve of dose-effect relationship and ED95 were calculated. A second dose of cisatracurium was then administrated (total volume 100 μg/kg). The recovery phase in each patient was observed upon T1 reaching the maximum blocking effect (100%).
  
  
  RESULTS
  Once the maximum blocking effect was reached, patients were intubated. There were 83 cases (92.2%) of patients with grade 1 and 7 (7.8%) patients with grade 2 intubating conditions. ED95 was 59.29, 55.88 and 45.39 μg/kg in adults, children, and infants, respectively. ED95 positively correlated with age. The clinical duration of neuromuscular blockade, effective action duration of neuromuscular blockade, and in vivo action duration of neuromuscular blockade in adults was longer than that in children (P<0.05), but shorter than in infants (P<0.05). However, there were no significant differences in the recovery index among groups (P>0.05).
  
  
  CONCLUSIONS
  Age influences the neuromuscular blocking effects of cisatracurium to a certain extent.
authors.affiliation: Department of Anesthesiology, Gongli Hospital of The Second Military Medical University Pudong New Area, Shanghai 200135, China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Anesthesiology, Gongli Hospital of 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, Zhejiang Tumor Hospital Hangzhou 310022, Zhejiang, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Department of Anesthesiology, Gongli Hospital of The Second Military Medical University Pudong New Area, Shanghai 200135, China.
authors.forename: Huachun
authors.initials: H
authors.lastname: Shen
authors.affiliation: Department of Anesthesiology, Gongli Hospital of The Second Military Medical University Pudong New Area, Shanghai 200135, China.
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Zhang
keywords: Cisatracurium; age; dose-effect relationship; recovery phase