title: Magnesium sulphate attenuates acute postoperative pain and increased pain intensity after surgical injury in staged bilateral total knee arthroplasty: a randomized, double-blinded, placebo-controlled trial.
abstract: BACKGROUND
  We evaluated the effect of magnesium sulphate on increased pain in 44 patients undergoing staged bilateral total knee arthroplasty (TKA).
  
  
  METHODS
  The magnesium group (n=22) and the control group (n=22) received magnesium sulphate and isotonic saline, respectively, throughout the surgery. Postoperative pain (visual analogue scale, VAS) at rest and the amounts of patient-controlled analgesia (PCA, fentanyl) and rescue analgesia (ketoprofen) administered during the first 48 h were compared between the two groups and within each group between the first and second TKA.
  
  
  RESULTS
  The VAS scores were significantly higher in the control group than in the magnesium group not only after the first TKA [29 (11) vs 19 (9) at 24 h and 33 (8) vs 24 (10) at 48 h; P=0.001] but also after the second TKA [44 (17) vs 20 (10) at 24 h and 43 (14) vs 25 (10) at 48 h; P<0.001]. In the control group, VAS scores were significantly higher for the second than for the first operated knee [44 (17) vs 29 (11) at 24 h and 43 (14) vs 33 (8) at 48 h; P<0.001 and P=0.006, respectively]. In the magnesium group, there were no significant differences in VAS scores between the first and second TKA. Magnesium significantly reduced the amounts of rescue analgesics and fentanyl administered over the first 48 h postoperatively.
  
  
  CONCLUSIONS
  Magnesium sulphate administration significantly reduced postoperative pain and minimized the difference in pain intensity between the first and second operations.
  
  
  BACKGROUND
  KCT0001361.
authors.affiliation: Department of Anaesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 13620 South Korea.
authors.forename: H-J
authors.initials: HJ
authors.lastname: Shin
authors.affiliation: Department of Anaesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 13620 South Korea.
authors.forename: E-Y
authors.initials: EY
authors.lastname: Kim
authors.affiliation: Department of Anaesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 13620 South Korea.
authors.forename: H-S
authors.initials: HS
authors.lastname: Na
authors.affiliation: Joint reconstruction centre, Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam-si, South Korea.
authors.forename: T K
authors.initials: TK
authors.lastname: Kim
authors.affiliation: Department of Anaesthesiology and Pain Medicine, Seoul St Mary's Hospital, Catholic University of Korea, Seoul, South Korea.
authors.forename: M-H
authors.initials: MH
authors.lastname: Kim
authors.affiliation: Department of Anaesthesiology and Pain Medicine, Seoul National University Bundang Hospital, 82, Gumi-ro 173 Beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do 13620 South Korea shdo@snu.ac.kr.
authors.forename: S-H
authors.initials: SH
authors.lastname: Do
mesh_terms: D059787:Acute Pain / Q000188:drug therapy*; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008278:Magnesium Sulfate / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy*; D064232:Visual Analog Scale
chemical_list: D008278:Magnesium Sulfate
keywords: magnesium; pain, postoperative; total knee arthroplasty