[Shivering during epidural anesthesia with and without fentanyl: comparative study.].

Background And Objectives: Most studies in the literature correlating epidural opioids to postoperative shivering were carried out with obstetric patients whose thermoregulation center response might be different from non-pregnant patients. Our study aimed at comparing intra and postoperative shivering and other complications of epidural block with and without fentanyl in patients submitted to varicose vein surgery under epidural anesthesia with 0.5% bupivacaine and 1:200,000 epinephrine.