Is the transdermal fentanyl patch an efficient way to achieve acute postoperative pain control?: A randomized controlled trial.

BACKGROUPD: This study investigated the plasma fentanyl concentration and efficacy of transdermal fentanyl patch (TFP) (25 µg/h) in the management of acute postoperative pain. METHODS: Patients undergoing laparoscopic cholecystectomy were randomly allocated to 2 groups. The TFP group (n = 30) received a single TFP 25 µg/ h to the anterior chest wall 14 h before operation. The IV group (n = 30) received a placebo patch. After the operation, intravenous fentanyl infusion (25 µg/h) was begun with loading dose 25 µg in the IV group and only normal saline in the TFP group. Plasma fentanyl levels were measured at admission, 1, 6, 12, 24, and 48 h postoperatively. Pain severity and adverse effects were evaluated too. RESULTS: The fentanyl level peaked 1 h after operation in the TFP group (3.27 ±â€Š0.34 ng/mL) and 24 h postoperatively in the IV group (2.9 ±â€Š0.42 ng/mL). Pain scores and the use of rescue analgesics were not significantly different between 2 groups. Respiratory depression was not happened in both groups. CONCLUSIONS: The TFP (25 µg/h) affixed 14 h before surgery reached a higher constant concentration than the same dose setting of a constant IV infusion of fentanyl after surgery. Although the concentration of fentanyl was higher than those of previous researches, there was no respiratory depression. But, there was no advantage of reducing pain score and the use of rescue analgesics. CLINICAL TRIAL REGISTRATION: (available at: http://cris.nih.go.kr, KCT0002221).