title: Continuous infiltration of local anaesthetic following total knee arthroplasty.
abstract: OBJECTIVE
  To determine whether continuous infiltration of local anaesthetic can reduce the pain score and morphine use over 48 hours after total knee arthroplasty (TKA).
  
  
  METHODS
  11 men and 43 women aged 50 to 82 years who underwent unilateral TKA for osteoarthritis were recruited. They were randomised into 3 groups. In group 1, 17 patients who acted as controls received patient-controlled analgesia (PCA) with intravenous morphine for 48 hours. In group 2, 16 patients received continuous infiltration of bupivacaine to the subcutaneous tissue and intra-articular space for 48 hours, in addition to PCA. In group 3, 21 patients received an intra-articular injection of local anaesthetic, followed by continuous infiltration of bupivacaine to the subcutaneous tissue and intraarticular space for 48 hours, in addition to PCA. For each patient, a visual analogue score (VAS) for pain was recorded postoperatively at 2, 4, 6, 12, 24, 36, and 48 hours. The total amount of morphine used was recorded at 24 and 48 hours.
  
  
  RESULTS
  Over 48 hours, the VAS for pain and morphine use was significantly higher in controls than patients in groups 2 and 3.
  
  
  CONCLUSIONS
  Continuous infiltration of local anaesthetic into the intra-articular space and subcutaneous tissues, in addition to PCA with intravenous morphine, provides significantly more pain relief and reduces morphine use.
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Singapore. johnnyongsgh@yahoo.com.sg
authors.forename: Johnny C A
authors.initials: JC
authors.lastname: Ong
authors.forename: Pak Lin
authors.initials: PL
authors.lastname: Chin
authors.forename: Chin Pak
authors.initials: CP
authors.lastname: Lin
authors.forename: Stephanie M C
authors.initials: SM
authors.lastname: Fook-Chong
authors.forename: Andrew
authors.initials: A
authors.lastname: Tang
authors.forename: Kuang Ying
authors.initials: KY
authors.lastname: Yang
authors.forename: Yang Kuang
authors.initials: YK
authors.lastname: Ying
authors.forename: Boon Keng
authors.initials: BK
authors.lastname: Tay
authors.forename: Tay Boon
authors.initials: TB
authors.lastname: Keng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D019645:Arthroplasty, Replacement, Knee; D002045:Bupivacaine / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007270:Injections, Intra-Articular; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D002045:Bupivacaine