title: Antihyperalgesic effects of dexmedetomidine on high-dose remifentanil-induced hyperalgesia.
abstract: BACKGROUND
  Dexmedetomidine is a highly selective α2 adrenergic agonist that has been shown to decrease the intensity of opioid-induced hyperalgesia (OIH). We aimed to investigate the antihyperalgesic effects of dexmedetomidine on high-dose remifentanil-induced hyperalgesia.
  
  
  METHODS
  Ninety American Society of Anesthesiologists physical status I-II patients undergoing laparoscopically assisted vaginal hysterectomy (LAVH) were randomly assigned to one of the following three groups, each of which received either dexmedetomidine (an initial dose of 1.0 µg/kg for 10 min, followed by a continuous infusion of 0.7 µg/kg/hr) or placebo saline 15 min before the induction of anesthesia and intraoperative remifentanil infusion: group C received a placebo and 0.05 µg/kg/min remifentanil; group RH received a placebo and 0.3 µg/kg/min remifentanil; and group DRH received dexmedetomidine and 0.3 µg/kg/min remifentanil.
  
  
  RESULTS
  The mechanical hyperalgesia threshold 24 hr after surgery was significantly lower in group RH than in the other two groups. Postoperative pain intensity using visual analog scale (VAS) and cumulative volume of a patient-controlled analgesia (PCA) containing morphine over 24 hr were significantly greater in group RH than in group DRH. The time to the first postoperative analgesic requirement was significantly shorter in group RH than in the other two groups. The desflurane requirement was significantly greater in group C than in the other groups. The frequency of hypotension and bradycardia was significantly higher, but shivering and postoperative nausea and vomiting were significantly lower in group DRH than in the other two groups.
  
  
  CONCLUSIONS
  High-doses of remifentanil induced hyperalgesia, which presented a decreased mechanical hyperalgesia threshold, enhanced pain intensity, a shorter time to first postoperative analgesic requirement, and greater morphine consumption, but dexmedetomidine efficiently alleviated those symptoms. Dexmedetomidine may be a novel and effective treatment option for preventing or attenuating OIH.
authors: Department of Anesthesiology and Pain Medicine, Wonkwang University College of Medicine, Iksan, Korea.
authors: Cheol
authors: C
authors: Lee
authors: Yeon-Dong
authors: YD
authors: Kim
authors: Ji-Na
authors: JN
authors: Kim
keywords: Dexmedetomidine; Opioid-induced hyperalgesia; Remifentanil
references: Anesth Analg. 2007 Jun;104(6):1397-403, table of contents
references: 17513631
references: Anesthesiology. 1997 May;86(5):1055-60
references: 9158354
references: Anesthesiology. 2012 Jun;116(6):1312-22
references: 22546966
references: Clin J Pain. 2008 Jul-Aug;24(6):479-96
references: 18574358
references: J Neurosci. 1985 Sep;5(9):2359-64
references: 2993542
references: Neuropharmacology. 1999 May;38(5):611-23
references: 10340299
references: Mol Pain. 2009 Dec 30;5:76
references: 20042082
references: Anesthesiology. 1988 Dec;69(6):818-23
references: 2848424
references: Anesth Analg. 2008 Jun;106(6):1741-8
references: 18499604
references: Br J Anaesth. 1999 Sep;83(3):372-80
references: 10655905
references: Eur J Pharmacol. 1988 May 20;150(1-2):9-14
references: 2900154
references: Anesthesiology. 1992 Jul;77(1):162-84
references: 1609990
references: Anesthesiology. 1987 Nov;67(5):868-9
references: 3674509
references: Anesthesiology. 1992 Jun;76(6):948-52
references: 1350889
references: Anaesthesia. 2007 Dec;62(12):1266-80
references: 17991265
references: Neuropharmacology. 1995 Oct;34(10):1219-37
references: 8570021
references: Anesthesiology. 1991 Jun;74(6):997-1002
references: 1675042
references: Anesthesiology. 2003 Jul;99(1):152-9
references: 12826855
references: Pain. 2012 May;153(5):974-981
references: 22365565
references: J Anaesthesiol Clin Pharmacol. 2012 Jan;28(1):86-91
references: 22345953
references: Anesth Analg. 1996 Sep;83(3):646-51
references: 8780298
references: Brain Res Bull. 2012 Mar 10;87(4-5):427-31
references: 22301064
references: Anesthesiology. 2006 Nov;105(5):1016-23
references: 17065897
references: Anesth Analg. 1992 Dec;75(6):940-6
references: 1359809
references: Anesthesiology. 1992 Dec;77(6):1134-42
references: 1361311
references: Korean J Anesthesiol. 2011 Sep;61(3):244-50
references: 22025948
references: Brain Res. 2009 Apr 6;1264:57-66
references: 19368840
references: Pain Med. 2010 Dec;11(12):1819-26
references: 21040434