Epidural versus intravenous fentanyl for postoperative analgesia following orthopedic surgery: randomized controlled trial.
OBJECTIVE
Controversy exists regarding the site of action of fentanyl after epidural injection. The objective of this investigation was to compare the efficacy of epidural and intravenous fentanyl for orthopedic surgery.


METHODS
A randomized double-blind study was performed in Hospital São Paulo.


METHODS
During the postoperative period, in the presence of pain, 29 patients were divided into two groups: group 1 (n = 14) received 100 microg of fentanyl epidurally and 2 ml of saline intravenously; group 2 (n = 15) received 5 ml of saline epidurally and 100 microg of fentanyl intravenously. The analgesic supplementation consisted of 40 mg of tenoxicam intravenously and, if necessary, 5 ml of 0.25% bupivacaine epidurally. Pain intensity was evaluated on a numerical scale and plasma concentrations of fentanyl were measured simultaneously.


RESULTS
The percentage of patients who required supplementary analgesia with tenoxicam was lower in group 1 (71.4%) than in group 2 (100%): 95% confidence interval (CI) = 0.001-0.4360 (P = 0.001, Fisher's exact test; relative risk, RR = 0.07). Epidural bupivacaine supplementation was also lower in group 1 (14.3%) than in group 2 (53.3%): 95% CI = 0.06-1.05 (P = 0.03, Fisher's exact test; RR = 0.26). There was no difference in pain intensity on the numerical scale. Mean fentanyl plasma concentrations were similar in the two groups.


CONCLUSIONS
Intravenous and epidural fentanyl appear to have similar efficacy for reducing pain according to the numerical scale, but supplementary analgesia was needed less frequently when epidural fentanyl was used.


BACKGROUND
NCT00635986.
Department of Anesthesia, Universidade Federal do Maranhão, São Luis, Maranhão, Brazil.
Marcelo Soares
MS
Privado
Adriana Machado
AM
Issy
Vera Lucia
VL
Lanchote
João Batista Santos
JB
Garcia
Rioko Kimiko
RK
Sakata
D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D000767:Anesthesia, Epidural; D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D002045:Bupivacaine / Q000008:administration & dosage; D004311:Double-Blind Method; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures; D010149:Postoperative Pain / Q000188:drug therapy*; D010894:Piroxicam / Q000008:administration & dosage / Q000031:analogs & derivatives; D012737:Sex Factors; D013997:Time Factors; D055815:Young Adult
D018686:Anesthetics, Intravenous; D010894:Piroxicam; D005283:Fentanyl; D002045:Bupivacaine; C032801:tenoxicam