title: Adding intrathecal morphine to unilateral spinal anesthesia results in better pain relief following knee arthroscopy.
abstract: OBJECTIVE
  Intrathecal morphine is administered to provide profound and prolonged analgesia, and to treat acute postoperative pain. We compared the effectiveness of hyperbaric bupivacaine alone and in combination with morphine for unilateral spinal anesthesia in patients undergoing knee arthroscopy.
  
  
  METHODS
  Sixty patients were randomly allocated to two groups to receive either 1.2 ml (6 mg) of 0.5% hyperbaric bupivacaine (group B; n = 30) or 1.2 ml of 0.5% hyperbaric bupivacaine containing 0.16 mg of morphine (group BM; n = 30). Spinal block was assessed by pinprick and a modified Bromage scale and compared between the operated and nonoperated sides. Visual analog scale (VAS) values, duration of analgesia, and total analgesic requirement of patients were recorded.
  
  
  RESULTS
  Patients in group BM had significantly lower VAS values on movement at 30 min and at 2, 4, 6, and 12 h postoperatively (P < 0.05 and P < 0.001, P < 0.001, P < 0.001, and P < 0.05, respectively). The total analgesic requirement in the first 24 h after surgery was significantly higher in group B (P < 0.001). Patients in group BM had a significantly longer duration of analgesia in the first 24 h postoperatively (P < 0.001). Motor blockade of the operated limb in group BM was similar to that in group B (P > 0.05), and motor blockade of the nonoperated limb in group BM was also similar to that in group B (P > 0.05).
  
  
  CONCLUSIONS
  We conclude that unilateral spinal anesthesia with hyperbaric bupivacaine plus 0.16 mg morphine is preferable to hyperbaric bupivacaine alone with respect to analgesic requirement, duration of analgesia, and VAS values.
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, University of Duzce, Konuralp, 81620, Duzce, Turkey.
authors.forename: Yavuz
authors.initials: Y
authors.lastname: Demiraran
authors.forename: Istemi
authors.initials: I
authors.lastname: Yucel
authors.forename: Gulgun Elif
authors.initials: GE
authors.lastname: Akcali
authors.forename: Erdem
authors.initials: E
authors.lastname: Degirmenci
authors.forename: Gulbin
authors.initials: G
authors.lastname: Sezen
authors.forename: Abdulkadir
authors.initials: A
authors.lastname: Iskender
mesh_terms: D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use*; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local; D001182:Arthroscopy; D002045:Bupivacaine; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D007717:Knee / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use*; D019148:Neuromuscular Blockade; D010100:Oxygen / Q000097:blood; D010147:Pain Measurement; D010149:Postoperative Pain / Q000517:prevention & control*; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000187:drug effects
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D010100:Oxygen; D002045:Bupivacaine