title: Effect of preemptive and preventive acetaminophen on postoperative pain score: a randomized, double-blind trial of patients undergoing lower extremity surgery.
abstract: OBJECTIVE
  To compare postoperative pain scores and rescue analgesic use in patients who received acetaminophen preoperatively or during skin closure versus those who received a placebo.
  
  
  METHODS
  Randomized, double-blind clinical trial.
  
  
  METHODS
  University-based, tertiary-care hospital.
  
  
  METHODS
  75 adult, ASA physical status 1 and 2 undergoing lower extremity orthopedic surgery.
  
  
  METHODS
  Patients were randomized to three groups. The control group received 100 mL of intravenous (IV) normal saline as a placebo. The preventive acetaminophen group received 100 mL of IV normal saline plus 15 mg/kg of acetaminophen prior to skin closure. The preemptive acetaminophen group received 15 mg/kg of IV acetaminophen combined with 100 mL of normal saline half an hour preoperatively.
  
  
  METHODS
  Pain was scored with the verbal rating scale and assessed 5 minutes before spinal anesthesia, and 6, 12, 18, and 24 hours after surgery. Total rescue meperidine consumption by each patient during the first 24 hours after surgery was also recorded.
  
  
  RESULTS
  Pain scores were lower in both preemptive and preventive acetaminophen groups at 6 hours after surgery than in the placebo group (P < 0.001). There were no differences in pain scores after 6 hours between the preemptive and preventive groups. Total analgesic consumption 24 hours after surgery was lowest in the preemptive acetaminophen group (P < 0.01). Average time to initial analgesic requirement was slightly longer in the preemptive and preventive acetaminophen groups than the control group (P < 0.01).
  
  
  CONCLUSIONS
  In patients undergoing lower extremity surgery with spinal anesthesia, both preventive and preemptive acetaminophen may enhance analgesia and decrease postoperative analgesic consumption.
authors.affiliation: Department of Anesthesiology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Khalili
authors.forename: Mohsen
authors.initials: M
authors.lastname: Janghorbani
authors.forename: Hamid
authors.initials: H
authors.lastname: Saryazdi
authors.forename: Abbas
authors.initials: A
authors.lastname: Emaminejad
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D000701:Analgesics, Opioid / Q000008:administration & dosage; D000775:Anesthesia, Spinal / Q000379:methods; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007866:Leg / Q000601:surgery*; D008297:Male; D008614:Meperidine / Q000008:administration & dosage; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000517:prevention & control*; D011229:Preanesthetic Medication / Q000379:methods
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D000082:Acetaminophen; D008614:Meperidine