title: Preemptive low-dose epidural ketamine for preventing chronic postthoracotomy pain: a prospective, double-blinded, randomized, clinical trial.
abstract: OBJECTIVE
  Chronic postthoracotomy pain is the most common long-term complication that occurs after a thoracotomy with a reported incidence of up to 80%. Although thoracic epidural analgesia is a widely used method for managing acute postthoracotomy pain, its effects seems questionable. The objective of this prospective, double-blinded, randomized, controlled trial was to assess the effect of preemptive low-dose epidural ketamine in addition to preemptive thoracic epidural analgesia on the incidence of chronic postthoracotomy pain.
  
  
  METHODS
  We analyzed 133 patients who were randomized to preemptive thoracic epidural analgesia either with or without ketamine (Group K: 0.12% levobupivacaine, 2 μg/mL of fentanyl, 0.2 mg/mL ketamine, total volume of 500 mL vs. Group KF: 0.12% levobupivacaine, 2 μg/mL of fentanyl, total volume of 500 mL). Pain at the thoracotomy scar site during rest and movement (coughing) was assessed at 2 weeks and 3 months after surgery using a visual analog scale. The incidence of allodynia and numbness was also evaluated.
  
  
  RESULTS
  There was no difference in the incidence of chronic postthoracotomy pain at 3 months between the 2 groups (67.7% in group K vs. 75% in group KF). The incidences of allodynia or numbness were not different between the 2 groups.
  
  
  CONCLUSIONS
  The addition of preemptive low-dose epidural ketamine (1.2 mg/h) to preemptive thoracic epidural analgesia did not have any beneficial effects in preventing chronic postthoracotomy pain.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Boramae Medical Center, Seoul National University, College of Medicine, 101 Daehang-no, Jongno-gu, Seoul, Korea.
authors.forename: Ho-Geol
authors.initials: HG
authors.lastname: Ryu
authors.forename: Chul-Joong
authors.initials: CJ
authors.lastname: Lee
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Jae-Hyon
authors.initials: JH
authors.lastname: Bahk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015360:Analgesia, Epidural / Q000379:methods; D000700:Analgesics / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology* / Q000517:prevention & control*; D011446:Prospective Studies; D013908:Thoracotomy / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D000700:Analgesics; D007649:Ketamine