title: Dose sparing of induction dose of propofol by fentanyl and butorphanol: A comparison based on entropy analysis.
abstract: BACKGROUND
  The induction dose of propofol is reduced with concomitant use of opioids as a result of a possible synergistic action.
  
  
  OBJECTIVE
  The present study compared the effect of fentanyl and two doses of butorphanol pre-treatment on the induction dose of propofol, with specific emphasis on entropy.
  
  
  METHODS
  Three groups of 40 patients each, of the American Society of Anaesthesiologistsphysical status I and II, were randomized to receive fentanyl 2 μg/kg (Group F), butorphanol 20 μg/kg (Group B 20) or 40 μg/kg (Group B 40) as pre-treatment. Five minutes later, the degree of sedation was assessed by the observer's assessment of alertness scale (OAA/S). Induction of anesthesia was done with propofol (30 mg/10 s) till the loss of response to verbal commands. Thereafter, rocuronium 1 mg/kg was administered and endotracheal intubation was performed 2 min later. OAA/S, propofol induction dose, heart rate, blood pressure, oxygen saturation and entropy (response and state) were compared in the three groups.
  
  
  METHODS
  Data was analyzed using ANOVA test with posthoc significance, Kruskal-Wallis test, Chi-square test and Fischer exact test. A P<0.05 was considered as significant.
  
  
  RESULTS
  The induction dose of propofol (mg/kg) was observed to be 1.1±0.50 in Group F, 1.05±0.35 in Group B 20 and 1.18±0.41 in Group B40. Induction with propofol occurred at higher entropy values on pre-treatment with both fentanyl as well as butorphanol. Hemodynamic variables were comparable in all the three groups.
  
  
  CONCLUSIONS
  Butorphanol 20 μg/kg and 40 μg/kg reduce the induction requirement of propofol, comparable to that of fentanyl 2 μg/kg, and confer hemodynamic stability at induction and intubation.
authors: Department of Anaesthesiology and Intensive Care, Gian Sagar Medical College and Hospital, Banur, Patiala, Punjab, India.
authors: Jasleen
authors: J
authors: Kaur
authors: Moningi
authors: M
authors: Srilata
authors: Durga
authors: D
authors: Padmaja
authors: Ramchandran
authors: R
authors: Gopinath
authors: Sukhminder Jit Singh
authors: SJ
authors: Bajwa
authors: Dorairay John
authors: DJ
authors: Kenneth
authors: Parasa Sujay
authors: PS
authors: Kumar
authors: Chalumuru
authors: C
authors: Nitish
authors: Wudaru Sreedhar
authors: WS
authors: Reddy
keywords: Butorphanol; entropy; fentanyl; propofol
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