title: Effects of intramuscular administration of lidocaine or bupivacaine on induction and maintenance doses of propofol evaluated by bispectral index.
abstract: BACKGROUND
  Interest in combining local and general anaesthesia has lead to studies investigating possible interactions. In a prospective, randomized, double-blind study, we tested whether local anaesthetics administered i.m. potentiate the hypnotic effect of propofol.
  
  
  METHODS
  Sixty patients (three groups, n=20) undergoing lower abdominal surgery with total i.v. propofol anaesthesia were investigated. Patients in Group B received i.m. bupivacaine (5 mg ml(-1)) 1 mg kg(-1), patients in Group L received i.m. lidocaine (100 mg ml(-1)) 2 mg kg(-1) and patients in Group C received i.m. saline 5 ml before operation. Hypnosis was measured with bispectral index (BIS).
  
  
  RESULTS
  The induction (BIS <45), and the maintenance doses of propofol (BIS between 40 and 50) were significantly less in Group B and Group L compared with the control group. Induction doses were 1.58 (SD 0.39), 1.56 (0.24) and 2.03 (0.33) mg kg(-1) respectively; P<0.0001. Maintenance doses were 6.33 (2.06), 7.08 (1.23) and 9.95 (2.02) mg kg(-1) respectively in the first hour; P<0.0001. Groups B and L were associated with an attenuated haemodynamic response to both induction and intubation.
  
  
  CONCLUSIONS
  I.M. administered local anaesthetics are associated with a decrease in both the induction and maintenance doses of propofol during total i.v. anaesthesia and a reduction in haemodynamic responses.
authors.affiliation: Department of Anaesthesiology, Istanbul University, Istanbul Medical Faculty, Capa 34390, Istanbul, Turkey. merthasta@yahoo.com
authors.forename: M
authors.initials: M
authors.lastname: Senturk
authors.forename: K
authors.initials: K
authors.lastname: Pembeci
authors.forename: F
authors.initials: F
authors.lastname: Menda
authors.forename: T
authors.initials: T
authors.lastname: Ozkan
authors.forename: B
authors.initials: B
authors.lastname: Gucyetmez
authors.forename: M
authors.initials: M
authors.lastname: Tugrul
authors.forename: E
authors.initials: E
authors.lastname: Camci
authors.forename: K
authors.initials: K
authors.lastname: Akpir
mesh_terms: D000328:Adult; D000758:Anesthesia / Q000379:methods*; D000768:Anesthesia, General; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001794:Blood Pressure; D002045:Bupivacaine / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate; D006801:Humans; D007273:Injections, Intramuscular; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D015742:Propofol / Q000008:administration & dosage*; D011446:Prospective Studies
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine; D015742:Propofol