title: Premedication with oral tramadol reduces severity of postoperative shivering after general anesthesia.
abstract: BACKGROUND
  Postanesthetic shivering (PAS) is an accompanying part of general anesthesia with different unpleasant and stressful complications. Considering the importance of proper prevention of PAS in order to reduce its related adverse complications in patients undergoing surgery, in this study, we investigated the effect of orally administrated tramadol in the prevention of this common complication of general anesthesia.
  
  
  METHODS
  In this prospective randomized double-blind clinical trial, 80 ASA I and II patients aged 15-70 years, scheduled for elective surgery under general anesthesia, were randomized to intervention (oral tramadol 50 mg) and placebo groups. PAS was evaluated during surgery and in the recovery room, and compared in the two study groups.
  
  
  RESULTS
  PAS was seen in 5 patients (12.5%) in the intervention group and 10 patients (25%) in the placebo group (P = 0.12). The prevalence of grade III and IV shivering was 7.5% (3/40) and 25% (10/40) in tramadol and placebo groups, respectively (P = 0.03).
  
  
  CONCLUSIONS
  The overall prevalence of PAS was not significantly different in the two study groups, but the higher grades of shivering which needed treatment were significantly lower in the tramadol group than in the placebo, and those patients who received tramadol experienced milder form of shivering. It is suggested that higher doses of tramadol would have better anti-shivering as well as analgesic effects. Studying different doses of tramadol would be helpful in this regard.
authors.affiliation: Anaesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Sayed Morteza
authors.initials: SM
authors.lastname: Heidari
authors.affiliation: Anaesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Rahimi
authors.affiliation: Anaesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Hasanali
authors.initials: H
authors.lastname: Soltani
authors.affiliation: Anaesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Sayed J
authors.initials: SJ
authors.lastname: Hashemi
authors.affiliation: Anaesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Shadi
authors.initials: S
authors.lastname: Shabahang
keywords: Oral; postanesthetic shivering; tramadol