title: The impact of long-lasting preemptive epidural analgesia before total hip replacement on the hormonal stress response. A prospective, randomized, double-blind study.
abstract: Recent studies suggest that preemptive analgesia may be effective in reducing postoperative pain. One physiologic explanation may be interference with the endogenous opioid response. We investigated whether long-lasting preoperative preemptive analgesia may have an effect on the hormonal stress response after total hip replacement.
  
  
  METHODS
  42 patients scheduled for elective hip replacement for coxarthrosis were randomized to receive, on the day before the operation, either 5 ml*h(-1) ropivacaine 0.2% (study group, n = 21) or 5 ml*h(-1) saline (control group, n = 21). Postoperative analgesia was achieved in both groups by patient-controlled epidural analgesia (PCEA) with ropivacaine 0.2%. The main outcome measure was the concentration of authentic beta-endorphin [1-31] in plasma up to 4 days after surgery. Additional parameters included concentrations of adrenocorticotrope hormone and cortisol.
  
  
  RESULTS
  Both groups were comparable concerning preoperative parameters and pain scores. Epidural blocks were sufficient in all patients for operative analgesia. Preemptive analgesia was performed for 11-20 hours in both groups and led to significantly decreased pain scores before surgery. Preemptive analgesia with epidural ropivacaine did not lead to decreased concentrations of beta-endorphin [1-31] before the start of surgery or in the postoperative period. Furthermore, no differences could be detected in the time course of beta-endorphin and adrenocorticotrope hormone after surgery. However, cortisol concentrations differed significantly between groups before the operation, but showed a comparable rise after surgery.
  
  
  CONCLUSIONS
  Differences in postoperative pain after preemptive analgesia do not seem to be due to an altered endogenous opioid response.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Jordan University, Queen Rania Street, PO BOX 13046, Amman 11942, Jordan. akaloweidi@hotmail.com
authors.forename: Abdelkarim S
authors.initials: AS
authors.lastname: Al Oweidi
authors.forename: Joachim
authors.initials: J
authors.lastname: Klasen
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Al-Mustafa
authors.forename: Sami A
authors.initials: SA
authors.lastname: Abu-Halaweh
authors.forename: Khaled R
authors.initials: KR
authors.lastname: Al-Zaben
authors.forename: Islam M
authors.initials: IM
authors.lastname: Massad
authors.forename: Ibrahim Y
authors.initials: IY
authors.lastname: Qudaisat
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D000368:Aged; D015360:Analgesia, Epidural; D019644:Arthroplasty, Replacement, Hip; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control*; D011446:Prospective Studies; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone