title: Intraspinal administration of morphine hydrochloride combined with low doses of bupivacaine in hemorrhoidectomy: a clinical randomized trial.
abstract: BACKGROUND
  Intrathecal local anesthetics, associated or not to opioids, is commonplace in anorectal surgery, but it is unknown which is the option with the best risk-benefit ratio. The main aim was to assess whether the combination of morphine (50 mcg) with low-dose bupivacaine (3 mg) in an intradural solution has a better analgesic short-term effect than bupivacaine alone at standard doses (5 mg) in hemorrhoidectomy.
  
  
  METHODS
  Sixty-six patients of any sex were randomly assigned to two alternative treatments and 63 patients were considered valid for analysis. Hyperbaric bupivacaine 3 mg combined with 50 mcg of intradural morphine hydrochloride (BUP-MOR group) was compared with 5 mg hyperbaric bupivacaine (BUP group). The primary outcome was pain evaluated through a visual analog scale (from 0 to 100 mm) at 24 hours post-surgery. The proportion of patients requiring rescue analgesia, and those presenting with motor blockade and other adverse events was also compared between the two groups.
  
  
  RESULTS
  BUP-MOR group showed a higher efficacy than BUP group in the visual analog scale at 24 hours postsurgery (15±12 vs. 33±22 mm; P<0.001). Also, BUP-MOR group presented a lower percentage of patients who needed rescue analgesia at resuscitation room (6.7% vs. 24.2%; P=0.08) and a lower proportion of patients who had motor blockade (23.3% vs. 51.5%; P=0.02), while they presented a non-significant increased incidence of urinary retention (23.3% vs. 9.0%; P=0.17).
  
  
  CONCLUSIONS
  The addition of intradural morphine allows a reduction in the dosage of local anesthetic improves short-term postoperative analgesia and is associated with less motor blockade.
authors.affiliation: Department of Anesthesiology, Resuscitation and Pain Treatment, Príncipe de Asturias University Hospital, Alcalá de Henares, Spain - mruizc@hotmail.com.|Department of Surgery, Medical and Social Sciences, University of Alcalá, Alcalá de Henares, Spain - mruizc@hotmail.com.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ruiz-Castro
authors.affiliation: Department of Anesthesiology, Resuscitation and Pain Treatment, Henares Hospital, Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: San José Santos
authors.affiliation: Unit of Clinical Pharmacology, Príncipe de Asturias University Hospital, Alcalá de Henares, Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Rodríguez-Miguel
authors.affiliation: Unit of Clinical Pharmacology, Príncipe de Asturias University Hospital, Alcalá de Henares, Madrid, Spain.|Department of Biomedical Sciences, University of Alcalá, Alcalá de Henares, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: de Abajo Iglesias
mesh_terms: D000698:Analgesia; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage*; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D061865:Hemorrhoidectomy; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D004338:Drug Combinations; D009020:Morphine; D002045:Bupivacaine