title: Effects of perineural tramadol on nerve conduction of sural nerve.
abstract: OBJECTIVE
  The aim of this study was to investigate whether tramadol had a dose-dependent blocking effect on nerve conduction when administered perineurally to the sural nerve of healthy volunteers.
  
  
  METHODS
  Twenty-four informed healthy subjects were randomized into four equal groups [Saline (placebo), 0.5% tramadol, 1% tramadol and 1.5% tramadol]. The study was designed to be double-blinded. Sensory nerve action potentials were recorded electroneurographically. Two milliliters of study solution was administered to the sural nerve perineurally at the level of the ankle with the guidance of a nerve stimulator. A sensory block was assumed to have developed when the amplitude of the averaged sensory nerve action potentials diminished below 80% of the baseline value in the subsequent recordings.
  
  
  RESULTS
  According to the electroneurographical recordings, none of the volunteers in the saline group had block. However, the block rates with 0.5%, 1% and 1.5% tramadol were 1/6, 4/6 and 6/6, respectively (p<0.05). The maximum decrement in the sensory action potential amplitudes with respect to baseline amplitudes (given as median values) were as follows: 7.8% with saline; 12.5% with 0.5% tramadol; 38.5% with 1% tramadol; and 77.5% with 1.5% tramadol (p<0.05). While the median duration of sensory block with 0.5% tramadol was 5 minutes, it was 15 minutes with 1% tramadol and 35 minutes with 1.5% tramadol.
  
  
  CONCLUSIONS
  Perineurally administered tramadol blocks sensory nerve conduction of the sural nerve in a dose-dependent manner.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Gazi University Faculty of Medicine, Ankara, Turkey. mbeyazova@gmail.com
authors.forename: Mehmet
authors.initials: M
authors.lastname: Beyazova
authors.forename: Ertan
authors.initials: E
authors.lastname: Öztürk
authors.forename: Murat
authors.initials: M
authors.lastname: Zinnuroğlu
authors.forename: Ismail
authors.initials: I
authors.lastname: Gökyar
authors.forename: Avni
authors.initials: A
authors.lastname: Babacan
authors.forename: Kadir
authors.initials: K
authors.lastname: Kaya
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D009431:Neural Conduction / Q000187:drug effects*; D013497:Sural Nerve / Q000187:drug effects* / Q000502:physiology; D014147:Tramadol / Q000008:administration & dosage / Q000494:pharmacology*; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D014147:Tramadol