EPIDURAL AND INTRAVENOUS FENTANYL PRODUCE EQUIVALENT EFFECTS DURING MAJOR SURGERY

Background: The benefit of epidural versus intravenous fentanyl admini stration for postoperative analgesia is controversial. In the current study, the intraoperative effects of epidural versus intravenous fenta nyl administration were compared during major surgery. Methods: Twenty elective patients scheduled for thoracoabdominal esophagectomy under general anesthesia with propofol infusion were randomly allocated to r eceive either intravenous or epidural boluses of 50-100 mu g fentanyl in a double-blind fashion to maintain hemodynamic stability. Plasma co rtisol and fentanyl, as well as total urinary catecholamines, were obt ained at the end of the operations. Results: Hemodynamic variations we re similar except that patients receiving epidural fentanyl had a lowe r incidence of heart rate reduction (>20% reduction from baseline, P < 0.05). There were no differences in mean intraoperative fentanyl (1,1 15 +/- 430 and 1,010 +/- 377 mu g, epidural and intravenous, respectiv ely) or propofol (2,281 +/- 645 and 2,452 +/- 1,169 mg) doses, number of boluses of fentanyl (nine in both groups), plasma fentanyl concentr ation (1.13 +/- 0.4 and 1.02 +/- 0.46 ng/ml), or number of anesthesiol ogists correctly identifying the site of fentanyl administration. simi larly, there were no differences in plasma glucose (8.9 +/- 1.8 and 9. 3 +/- 1.8 mM) and cortisol (696 +/- 446(1 and 846 +/- 257 mM), or urin ary epinephrine (12 +/- 3.7 and 13.1 +/- 9.2, mu g/sample) and norepin ephrine (42.7 +/- 26.7 and 39.1 +/- 27.6, mu g/sample). Conclusions: T here appears to be no clinical advantage to epidural administration of fentanyl over intravenous administration during anesthesia for major surgery.