title: Effective doses of cisatracurium in the adult and the elderly.
abstract: BACKGROUND
  There are few information about the differences of the effective dose (ED) of cisatracurium between the adult and the elderly. We investigated the ED and the onset time of cisatracurium in the adults and the elderly.
  
  
  METHODS
  We studied two hundred patients of the adults aged 20 through 64 years and the elderly aged ≥ 65 years, with American Society of Anesthesiologists physical status I or II. Each 100 patients with 20 patients of each dose group, randomly selected from 30, 40, 50, 60 or 70 µg/kg of cisatracurium, were randomly allocated to the adults and the elderly groups. We recorded the 0.1 Hz single twitch responses of the adductor pollicis and the onset times to maximal blockade. The magnitude of muscle relaxation was recorded by using an acceleromyography. The effect of cisatracurium on single twitch was calculated as percent reduction. After converting each drug dose into logarithm and percent reduction of the muscle reduction into probit, the EDs representing the muscle relaxation effects of 5%, 25%, 50%, 75% and 95% were estimated using the linear regression analysis.
  
  
  RESULTS
  No significant differences were found in age, weight, height, or body mass index within or between the groups. The ED50and ED95of the adult group were 35.39 and 59.58 µg/kg. The ED50and ED95of the elderly group were 34.89 and 55.50 µg/kg, respectively. The onset times were 375.4 ± 76.9 seconds in the adult group and 369.1 ± 70.0 seconds in the elderly group.
  
  
  CONCLUSIONS
  The ED and the onset time were not significantly different between the adult and the elderly.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: Jeong Ho
authors.identifier: 0000-0003-4447-2838
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: Yoon Chan
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: Soo Il
authors.initials: SI
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: Sang Yoong
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: So Ron
authors.initials: SR
authors.lastname: Choi
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: Jong Hwan
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: Chan Jong
authors.initials: CJ
authors.lastname: Chung
authors.affiliation: Department of Anesthesiology and Pain Medicine, Dong-A University Hospital, Busan, Korea.
authors.forename: Seung Cheol
authors.identifier: 0000-0001-8669-5517
authors.initials: SC
authors.lastname: Lee
keywords: Aged; Cisatracurium