title: Postoperative pain and systemic inflammatory stress response after preoperative analgesia with clonidine or levobupivacaine: a randomized controlled trial.
abstract: OBJECTIVE
  With adequate control of perioperative pain it is possible to control central and peripheral inflammatory responses to surgery and influence patient outcomes. Use of analgesics before the pain stimulus (preventive analgesia) obstructs development of neuroplastic changes in the central nervous system and reduces pain. Our investigation hypothesis is that preoperative central (epidural or intrathecal) clonidine will reduce postoperative pain and the systemic inflammatory stress response more effectively than levobupivacaine.
  
  
  METHODS
  Randomized controlled study.
  
  
  METHODS
  Forty-two patients undergoing colorectal resection surgery were allocated into three groups receiving a preoperative epidural dose of (i) clonidine 5 microg/kg (n = 17), (ii) levobupivacaine 2.5 mg/ml (n = 12) or (iii) saline as a control group (n = 13). Procalcitonin, interleukin-6 and pain levels were assessed before operation, 1 h after starting, and then at 1, 6, 12 and 24 h after operation.
  
  
  RESULTS
  There were no significant differences between the groups of patients in age, sex, body-mass index, body surface area and operation time. We demonstrated significant reduction (P < 0.05) in levels of procalcitonin and interleukin-6 in the preoperative clonidine group compared with the preoperative levobupivacaine and control groups. Postoperative pain levels at rest and on movement were significantly lower (P < 0.05) in the clonidine group, especially 1 h after surgery (VAS 0.82 and 1.18), than in the levobupivacaine group (VAS 5.25 and 6.67) and the control group (VAS 7.08 and 8.31).
  
  
  CONCLUSIONS
  These results support the importance of the central effect of clonidine on pain pathways and blockade of the systemic inflammatory stress response.
authors.affiliation: Anesthesiology, Resuscitation and Intensive Care Medicine Clinic, University Hospital Dubrava, Zagreb, Croatia, jpersec@net.amis.hr.
authors.forename: Jasminka
authors.initials: J
authors.lastname: Persec
authors.forename: Zoran
authors.initials: Z
authors.lastname: Persec
authors.forename: Ino
authors.initials: I
authors.lastname: Husedzinovic
mesh_terms: D000368:Aged; D000700:Analgesics / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage; D002045:Bupivacaine / Q000008:administration & dosage / Q000031:analogs & derivatives; D003000:Clonidine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D000077554:Levobupivacaine; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000187:drug effects*; D010149:Postoperative Pain / Q000175:diagnosis* / Q000517:prevention & control*; D011300:Preoperative Care; D018746:Systemic Inflammatory Response Syndrome / Q000175:diagnosis / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000700:Analgesics; D000779:Anesthetics, Local; D000077554:Levobupivacaine; D003000:Clonidine; D002045:Bupivacaine