title: Intravenous paracetamol as adjunctive treatment for postoperative pain after cardiac surgery: a double blind randomized controlled trial.
abstract: BACKGROUND
  Nonsteroidal anti-inflammatory drugs and opioids are routinely used after cardiac surgery in order to mitigate postoperative pain; however, these drugs are burdened by side effects. Tramadol and paracetamol are believed to be lacking in such side effects. The aim of this study was to examine the efficacy of intravenous paracetamol as an adjunctive analgesic to a tramadol-based background analgesia after cardiac surgery.
  
  
  METHODS
  A total of 113 patients participated in this single center, placebo-controlled, double-blind, randomized trial. Fifty-six patients were randomized to receive paracetamol and 57 to placebo. Intravenous study drug (1 g) was administered 15 min before the end of surgery and every 6h for 72 h. Standard analgesia (tramadol) and anti-emetic prophylactic regimen (ondansetron) were available to both patient groups. Postoperative pain was evaluated by visual analog scale, and it was measured at rest and during a deep breath. A rescue dose of 2-5 mg of intravenous morphine was administered whenever the VAS score was greater than 3.
  
  
  RESULTS
  Baseline characteristics were equivalent between the two groups. At 12, 18, 24 h after the end of operation, patients who received paracetamol had significantly less pain at rest (p=0.0041, 0.0039, 0.0044, respectively); after this time the two groups did not differ. During a deep breath the difference was significant only at 12 h (p=0.0040). Paracetamol group required less cumulative morphine than placebo group (48 mg vs 97 mg) even if the difference did not reach statistical significance (p=0.274).
  
  
  CONCLUSIONS
  In patients undergoing cardiac surgery, intravenous paracetamol in combination with tramadol provides effective pain control.
authors.affiliation: Department of Anesthesia and Intensive Care, Sant'Orsola-Malpighi Hospital, University of Bologna, Italy. iolter.cattabriga@fastwebnet.it
authors.forename: Iolter
authors.initials: I
authors.lastname: Cattabriga
authors.forename: Davide
authors.initials: D
authors.lastname: Pacini
authors.forename: Gaia
authors.initials: G
authors.lastname: Lamazza
authors.forename: Francesco
authors.initials: F
authors.lastname: Talarico
authors.forename: Roberto
authors.initials: R
authors.lastname: Di Bartolomeo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Grillone
authors.forename: Letizia
authors.initials: L
authors.lastname: Bacchi-Reggiani
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage* / Q000009:adverse effects; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage* / Q000009:adverse effects; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D017024:Chemotherapy, Adjuvant; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D020250:Postoperative Nausea and Vomiting / Q000139:chemically induced; D014147:Tramadol / Q000627:therapeutic use*
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D000082:Acetaminophen; D014147:Tramadol