Transdermal fentanyl as an adjuvant to paravertebral block for pain control after breast cancer surgery: A randomized, double-blind controlled trial

OBJECTIVE: The aim of this study is to investigate the effect of transdermal fentanyl (TDF) as an adjuvant to paravertebral block (PVB) for pain control after breast cancer surgery. PATIENTS AND METHODS: This randomized, double-blind trial included fifty females with breast cancer scheduled for surgery. They were randomly allocated into one of two equal groups. The TDF group used transdermal fentanyl patches (TFPs) 25 μg/h applied 10 h preoperative then PVB with 20 mL of bupivacaine 0.25% was done before induction of general anesthesia. The PVB group used placebo patches in addition to PVB the same way as TDF group. Postoperative pain was assessed with a visual analog scale (VAS) score up to 48 h. Intravenous morphine 0.1 mg/kg was given when the VAS is ≥ 3 or on patient request. The primary outcome measures were the time to first request for analgesia and the total analgesic consumption in the first 48 h. RESULTS: Relative to the VAS score reading was 30 min. After the end of surgery, VAS score decreased significantly in the two groups up to 48 postoperative hours and was significantly lower in TDF group up to 24 h. The time to first request of additional analgesia was significantly longer, and total dose of morphine consumption was significantly lower in TDF group (P < 0.001, and P = 0.039, respectively). CONCLUSION: TFPs releasing 25 μg/h is a safe and effective adjuvant to PVB after breast cancer surgery. It provides adequate analgesia with reduction of opioid consumption and minimal adverse effects.