Materials and Methods: Accordingly, 100 patients scheduled for outpatient gynecologic procedures were studied in two randomly assigned groups. All patients received total intravenous anesthesia for induction and maintenance with remifentanil-propofol and fentanyl-propofol in remifentanil and fentanyl groups, respectively. The incidence and severity of shivering, as well as core body temperature, hemodynamic variations, and probable postoperative complications were evaluated and recorded based on the aim of the study.

Results: Based on the results, there were no significant differences in demographic data. On the other hand, the incidence and severity of shivering were significantly higher in the remifentanil group compared to the fentanyl group (P < 0.001) although core body temperatures did not differ between the two groups (P > 0.05). Finally, no significant difference was observed in hemodynamic changes and other postoperative complications between the two groups (P > 0.05).

Conclusions: In general, remifentanil is a very short-acting and safe opioid for ambulatory procedures. However, it is associated with a higher incidence and severity of shivering as compared to other opioids unrelated to intraoperative hypothermia. Thus it must be noted that some strategies are needed to prevent this complication.