Comparison of efficacy of different doses of remifentanil combined with propofol for colonoscopy

Objective To compare the efficacy of different does of remifenanil combined with propofol for colonoscopy.Methods Ninety ASA Ⅰ or Ⅱ patients,aged 35-63 yr,weighing 45-72 kg,scheduled for elective painless outpatient colonoscopy,were randomly divided into 3 groups (n =30 each):remifentanil 0.2 μg/kg group (group Ⅰ),remifentanil 0.5 μg/kg group (group lⅡ) and remifentanil 1.0 μg/kg group (group Ⅲ).In groups Ⅰ-Ⅲ,remifentanil 0.2,0.5 and 1.0μg/kg were injected over 60 s,respectively,and then propofol 1.0 mg/kg was injected intravenously for induction.The colonoscope was inserted after loss of eyelash reflex.When body movement appeared during examination,remifentanil 0.1 μg/kg + propofol 0.5 mg/kg,remifentanil 0.25 μg/kg + propofol 0.5 mg/kg,and remifentanil 0.5μg/kg+ propofol 0.5 mg/kg were added in groups Ⅰ,Ⅱ and Ⅲ,respectively.The operation time,induction time,emergence time,examination room discharge time,and body movement,hypotension,bradycardia,hypoxemia and respiratory depression during operation were recorded.Results There was no significant difference in the operation time,induction time,emergence time,and examination room discharge time between the three groups (P ＞ 0.05).Compared with group Ⅰ,the incidence of body movement was significantly decreased,and the incidences of hypotension and respiratory depression were increased in group Ⅱ,and the incidence of body movement was significantly decreased,and the incidences of hypotension,hypoxemia,bradycardia and respiratory depression were increased in group Ⅲ (P ＜ 0.05).The incidences of hypoxemia,bradycardia and respiratory depression were significantly higher in group Ⅲ than in group Ⅱ (P ＜0.05).Conclusion The optimum dose of remifentanil is 0.5 μg/kg when combined with propofol for colonoscopy. Key words: Piperidines;  Propofol;  Colonoscopy