Backgrond & Objectives: Perioperartive shivering is a common complication which interferes with monitoring of patients and it increases oxygen consumption (up to 500%) which can be life-threating in patients with a low cardio pulmonary reserve. This study compared the efficiency and complications of two perioperative antishivering drugs. (Tramadol and Meperidine).

  Methods: All of the 70 patients under went cesarean section with spinal Anesthesia, were categorized in two groups of 35 persons, and treated as clinical trial, double blind with tramadol and meperidine. Then they were compared in terms of the interval between administration of drugs and stoping of shivering and their complications.

  Results : The mean age in patient were 27 years, youngest one was 17 and the oldest was 39 years. The average interval of stopping of shivering during tramadol using (2.57 min) is less than meperidine (6.24 min). The frequency of nausea and vomiting in meperidine group was more than that of the tramadol group. Regarding the incidence of pruritus and sedation after using of drug in both groups, there was no considerable difference between them. Respiratory and pulse rate changes, and decreasing of arterial oxygen saturation in post injection period to preinjection period of meperidine, didn't show any significant changes. In systolic and diastolic blood pressure changes, there was no significant change in both groups.

  Conclusion: Perioperative shivering treatment by tramadol is better than meperidine because of its faster onset of stopping of shivering and its low complications in cesarean section with spinal anesthesia.

  Background and objectives: High incidence of postoperative shivering leads to complications such as increased oxygen consumption, intracranial & intraocular pressure and pain. Some drugs including pethedine, dexamethasone and doxapram are used for prevention of shivering. The aim of this study is to compare the effect of dexamethasone and doxapram in prevention of post-anesthetic shivering.

  Methods: This study is a double blind clinical trial including 90 patients in ASA 1 and 2 classes. The patients were under general anesthesia for elective abdominal and chest surgery with same the anesthesia techniques. Samples were randomly divided into three groups (two drug received groups and one control group). First group received dexamethasone 0.1 mg/kg, the second group doxapram 0.75 mg/kg and the control group 3 ml of distilled water as injection. The visible shivering observed after each treatment. Collected data were analyzed using Chi-square, Fisher exact and ANOVA tests By SPSS 16 and p ≤ 0.05 was considered significant.

  Results: Our results showed a significant difference between shivering in drug received and control groups. Shivering was significantly decreased in drug received groups (p = 0 . 05) but there was no significant difference between them.

  Conclusion: This study showed that both drugs of dexamethasone and doxapram are effective in prevention of post-anesthetic shivering and can be substituted with pethedine. In addition to antishivering effect, doxapram has a respiratory stimulant effect that is, that is clinically important in postoperative stage.