title: Intradermal injection of tramadol has local anesthetic effect: a comparison with lidocaine.
abstract: BACKGROUND
  We observed that intravenous retention of tramadol with a pneumatic tourniquet on the arm inflated to 70 mmHg for one minute could effectively reduce the subsequent propofol injection pain. Tramadol is a central-acting analgesic. The local analgesic effect of tramadol on reducing propofol injection pain is not well known.
  
  
  METHODS
  To explore this problem we conducted a double-blind study on intradermal injections of tramadol 25 mg, lidocaine 5 mg and normal saline (all in 0.5 ml volume) which were given to each of the 10 healthy volunteers on the forearm at random. Pain on injections and the degree of local analgesia to pinprick, light touch and cold at each injection site were scored on a 0-4 scale at designated intervals.
  
  
  RESULTS
  5% tramadol, similar to 1% lidocaine, rendered loss of sensation to pin prick, light touch and cold for 30 min after intradermal injection as compared with normal saline (p < 0.01).
  
  
  CONCLUSIONS
  We concluded that intradermal injection of tramadol or lidocaine can produce local anesthetic effect.
authors.affiliation: Department of Anesthesia, Show-Chwan Memorial Hospital, Changhua, Taiwan, R.O.C.
authors.forename: W W
authors.initials: WW
authors.lastname: Pang
authors.forename: M S
authors.initials: MS
authors.lastname: Mok
authors.forename: D P
authors.initials: DP
authors.lastname: Chang
authors.forename: T F
authors.initials: TF
authors.lastname: Yang
authors.forename: C H
authors.initials: CH
authors.lastname: Lin
authors.forename: M H
authors.initials: MH
authors.lastname: Huang
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007271:Injections, Intradermal; D008012:Lidocaine / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D014147:Tramadol / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000779:Anesthetics, Local; D014147:Tramadol; D008012:Lidocaine