title: Intermittent subcutaneous morphine regimen for postoperative pain management following abdominal hysterectomy regarding morphine- and beta-endorphin systemic concentrations.
abstract: OBJECTIVE
  Systemic β-endorphin, an endogenous opioid and stress hormone, has been demonstrated to correlate with the postoperative pain intensity, however its putative role as a postoperative pain biomarker has not been cleared.
  
  
  METHODS
  Thirty patients scheduled for elective hysterectomy were included into the study. Postoperative pain was assessed by a numeric rating scale from 0 to 10. Plasma morphine concentrations were determined using high performance liquid chromatography with UV detection. Plasma β-endorphin concentrations were measured by a radioimmunoassay.
  
  
  RESULTS
  Administration of morphine in intravenous infusion turned out to be a markedly better method of morphine administration up to 4th hour postoperatively regarding both drug concentration and pain rating. A significant correlation between systemic β-endorphin concentration and pain rating at the 4th postoperative hour was found. No association between morphine and β-endorphin concentrations was detected.
  
  
  CONCLUSIONS
  Systemic β-endorphin is not an appropriate pain marker in postoperative gynaecologic patients.
authors: Department of Clinical Pharmacy and Biopharmacy, Poznań University of Medical Sciences, Poznań, Poland.
authors: Danuta
authors: D
authors: Szkutnik-Fiedler
authors: Hanna
authors: H
authors: Billert
authors: Edmund
authors: E
authors: Grzeskowiak
authors: Michal
authors: M
authors: Gaca
authors: Pawel
authors: P
authors: Panienski
authors: Magdalena
authors: M
authors: Borowicz
authors: Grzegorz
authors: G
authors: Breborowicz
mesh_terms: D000005:Abdomen / Q000601:surgery; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016903:Drug Monitoring / Q000379:methods; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007044:Hysterectomy / Q000379:methods; D055104:Infusions, Subcutaneous / Q000379:methods; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage* / Q000097:blood*; D010149:Postoperative Pain / Q000097:blood / Q000188:drug therapy*; D016896:Treatment Outcome; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D000701:Analgesics, Opioid; D015415:Biomarkers; D001615:beta-Endorphin; D009020:Morphine