title: Comparative evaluation of dexmedetomidine and clonidine with low dose ropivacaine in cervical epidural anesthesia for modified radical mastectomy: A prospective randomized, double-blind study.
abstract: BACKGROUND
  Alpha-2 adrenergic agonists clonidine and dexmedetomidine, are well known to produce analgesia through an opioid independent mechanism. Alpha-2 agonists are used as an adjuvant to local anesthetic agents to extend the duration of spinal, epidural and brachial plexus blocks.
  
  
  OBJECTIVE
  We compared clonidine and dexmedetomidine as an adjuvant to Ropivacaine in cervical epidural anesthesia (CEA) with respect to onset and duration of sensory block, duration of analgesia and adverse effects.
  
  
  METHODS
  A total 150 American Society of Anesthesiologists Class I or II adult female patients who were scheduled to undergo modified radical mastectomy were randomly allocated to the following two groups to receive CEA: Group D receive 15 mL of 0.375% ropivacaine combined with 1 μg/kg of dexmedetomidine; Group C received 15 mL of 0.375% ropivacaine combined with 1.5 μg/kg of clonidine. The onset of sensory block, duration of analgesia, mean arterial pressure (MAP), heart rate (HR), sedation scores, and the incidences of adverse effects, such as hypotension, bradycardia, and oxygen desaturation were recorded.
  
  
  RESULTS
  The addition of dexmedetomidine to ropivacaine (Group D) resulted in faster onset of sensory block time compared with the addition of clonidine to ropivacaine (Group C) (95% confidence interval [CI]: 14.53 ± 2.96 vs. 16.72 ± 4.43 P = 0.032). The duration of analgesia block in Group D was significantly longer than that in Group C (95% CI: 234.65 ± 23.76 vs. 286.76 ± 34.65; P = 0.037). The Ramsay sedation score at in Group D were significantly higher between 20 and 60 min as compared to Group C (P < 0.022). MAP level and HR level in Group D and Group C were comparable.
  
  
  CONCLUSIONS
  The addition of dexmedetomidine to low dose ropivacaine for CEA could shorten the onset of sensory block and extend the duration of analgesia with optimum sedation without episodes of hypoxemia as compared to addition of clonidine to ropivacaine.
authors.affiliation: Department of Anaesthesiology, Subbaiah Institute of Medical Sciences, Shimoga, Karnataka, India.
authors.forename: Shivakumar M
authors.initials: SM
authors.lastname: Channabasappa
authors.affiliation: Department of Surgery, Subbaiah Institute of Medical Sciences, Shimoga, Karnataka, India.
authors.forename: Gopinath H
authors.initials: GH
authors.lastname: Venkatarao
authors.affiliation: Department of Anaesthesiology, Subbaiah Institute of Medical Sciences, Shimoga, Karnataka, India.
authors.forename: Shobha
authors.initials: S
authors.lastname: Girish
authors.affiliation: Department of Surgery, Subbaiah Institute of Medical Sciences, Shimoga, Karnataka, India.
authors.forename: Nandakishore K
authors.initials: NK
authors.lastname: Lahoti
keywords: Cervical epidural anesthesia; clonidine; dexmedetomidine; modified radical mastectomy; ropivacaine