title: Perioperative ketamine does not prevent chronic pain after thoracotomy.
abstract: Thoracotomy is often responsible for chronic pain, possibly of neuropathic origin. To confirm preclinical studies, the preventive effects of perioperative ketamine were tested in a randomized, double-blind, placebo-controlled clinical trial on persistent neuropathic pain after thoracotomy. Eighty-six patients scheduled for thoracotomy under standardised general anaesthesia were randomised to receive either ketamine (1 mg kg(-1) at the induction, 1 mg kg(-1) h(-1) during surgery, then 1 mg kg(-1) during 24 h; n=42) or normal saline (n=44). Postoperative analgesia included a single dose of intrapleural ropivacaine, intravenous paracetamol and nefopam, and patient-controlled intravenous morphine. Vital parameters and analgesia were recorded during the 48 first postoperative hours. Seventy-three patients were followed up. The patient's chest was examined 1-2 weeks, 6 weeks and 4 months after surgery. At the last two observations, spontaneous pain score over a one-week period (visual analogue scale), neuropathic pain score (NPSI), and intake of analgesics, were assessed. No drug affecting neuropathic pain (except opiates) was given during the follow-up. Two patients in each group were lost to follow-up after the 6 week visit. Ketamine improved immediate postoperative pain, but the groups were similar in terms of neuropathic pain and intake of analgesics, 6 weeks (NPSI score: ketamine: 1.25 [0-4.125]; placebo: 1 [0-4]) and 4 months after surgery. Thus, ketamine given in 24-h infusion failed to prevent chronic neuropathic pain after thoracotomy. Other perioperative preventive long-lasting treatments or techniques could be tested in this context.
authors.affiliation: CHU Clermont-Ferrand, Pôle Anesthésie-Réanimation-SAMU-SMUR, Hôpital Gabriel-Montpied, F-63003 Clermont-Ferrand, France. cduale@chu-clermontferrand.fr
authors.forename: Christian
authors.initials: C
authors.lastname: Dualé
authors.forename: Fabrice
authors.initials: F
authors.lastname: Sibaud
authors.forename: Virginie
authors.initials: V
authors.lastname: Guastella
authors.forename: Laurent
authors.initials: L
authors.lastname: Vallet
authors.forename: Yves-Alain
authors.initials: YA
authors.lastname: Gimbert
authors.forename: Hammou
authors.initials: H
authors.lastname: Taheri
authors.forename: Marc
authors.initials: M
authors.lastname: Filaire
authors.forename: Pierre
authors.initials: P
authors.lastname: Schoeffler
authors.forename: Claude
authors.initials: C
authors.lastname: Dubray
mesh_terms: D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage; D000778:Anesthetics, Dissociative / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007430:Intraoperative Care / Q000379:methods / Q000706:statistics & numerical data*; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009294:Narcotics / Q000008:administration & dosage; D009437:Neuralgia / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy* / Q000503:physiopathology / Q000517:prevention & control; D010919:Placebos; D011182:Postoperative Care / Q000379:methods / Q000706:statistics & numerical data; D011300:Preoperative Care / Q000379:methods / Q000706:statistics & numerical data; D013908:Thoracotomy / Q000009:adverse effects*; D017211:Treatment Failure
chemical_list: D018712:Analgesics, Non-Narcotic; D000778:Anesthetics, Dissociative; D000779:Anesthetics, Local; D009294:Narcotics; D010919:Placebos; D007649:Ketamine