ABSTRACT
Objective To observe the effects of obesity on dose-response curve of rocuronium in female patients and calculate ED9 5 of rocuronium.Methods Eighty female patients,aged 18-45 years, falling into ASA grade Ⅰ or Ⅱ,schedualed for elective surgery under general anesthesia,undergoing surgery less than 1.5 h,were included in the study.The patients with body mass index of 20-25 kg/m2 as group N were randomized to divided group N1,group N2,group N3 and group N4.Anoth-er 40 patients with body mass index of 30-35 kg/m2 as group B were randomized to divided group B1, group B2,group B3 and group B4.When the first twitch height of TOF (T1)was 100%,groups N1-N4 and groups B1-B4 patients were injected rocuronium 0.075,0.1,0.1 5,0.3 mg/kg respectively. The first dose of rocuronium in each group,T1 maximum inhibition degree and onset time were re-corded.The relationship between probit-transformed depression of T1 and the logarithm dose of rocu-ronium was analyzed by linear regression.ED50 and ED9 5 of rocuronium in obese and normal body weight patients were calculated.Results Dose-response curve equation of each group were Y1 =3.464X1 -2.23 and Y2 = 3.843X2 - 2.750 respectively(P < 0.05 ).The ED50 and ED9 5 (95% CI)of rocuronium were 0.122 (0.092-0.1 65 )mg/kg and 0.324 (0.242-0.433 )mg/kg in group N,and were 0.103 (0.078-0.133)mg/kg and 0.25 1 (0.1 93-0.326)mg/kg in group B.Conclusion Obesity significantly affects the dose-response curve of young women and can enhance the sensitivity of them to the rocuronium.The ED9 5 of obese patients is 0.25 1 mg/kg.