title: Effects of perineural administration of dexmedetomidine in combination with levobupivacaine in a rat sciatic nerve block.
abstract: OBJECTIVE
  The aim of this study was to assess if perineural administration of dexmedetomidine combined with levobupivacaine increases the duration of the sensory and motor blockade of a sciatic peripheral nerve block in rats.
  
  
  METHODS
  Forty male Sprague-Dawley rats were randomly divided into 5 experimental groups: Group 1, sham; Group 2, perineural levobupivacaine (0.2 mL of a 0.5% solution) and subcutaneous saline; Group 3, perineural levobupivacaine (0.2 mL of a 0.5% solution) plus dexmedetomidine (20 µg/kg dexmedetomidine) and subcutaneous saline; Group 4, perineural saline and subcutaneous dexmedetomidine; and Group 5, perineural saline and subcutaneous saline. Pain reflexes in response to a thermal stimulus were measured at 0 and 240 minutes after drug administration by using a hot-plate and tail-flick tests. Neurobehavioral status, including sensory and motor functions, was assessed by an investigator who was blinded to the experimental groups every 30 minutes until normal functioning resumed.
  
  
  RESULTS
  The sensory and motor blockades of the rats did not increase in the treatment with dexmedetomidine plus levobupivacaine when compared with the treatment with levobupivacaine alone at all the time points (P > 0.05). Compared with rats in Group 2, those in Group 3 showed significantly higher latency times at 30 and 60 minutes in the hot plate test (P < 0.01). At 30 and 60 minutes, the latency times of the rats in Group 3 were longer than those in Group 2 in the tail-flick test (P < 0.01). Furthermore, the durations of the complete sensory and motor blockade were similar when treatment with levobupivacaine plus dexmedetomidine was compared with treatment with levobupivacaine alone.
  
  
  CONCLUSIONS
  A 20µg/kg dose of dexmedetomidine added to levobupivacaine did not increase the duration of the sensory and motor blockades in rats. However, treatment with dexmedetomidine plus levobupivacaine increased the quality of analgesia in rats.
authors.affiliation: Department of Anesthesiology and Reanimation, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ali Erdogan
authors.affiliation: Department of Physiology, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Alaaddin
authors.initials: A
authors.lastname: Polat
authors.affiliation: Department of Anesthesiology and Reanimation, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Aytac
authors.initials: A
authors.lastname: Yucel
authors.affiliation: Department of Anesthesiology and Reanimation, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Mustafa Said
authors.initials: MS
authors.lastname: Aydogan
authors.affiliation: Department of Pharmacology, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Parlakpinar
authors.affiliation: Department of Physiology, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Suat
authors.initials: S
authors.lastname: Tekin
authors.affiliation: Department of Anesthesiology and Reanimation, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Durmus
authors.affiliation: Department of Anesthesiology and Reanimation, Inonu University, Faculty of Medicine, Malatya, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozcan Ersoy
keywords: anesthesia adjuvants; dexmedetomidine; levobupivacaine; nerve block; sciatic nerve