The impact of intravenous dexamethasone on the efficacy and duration of analgesia of paravertebral block in breast cancer surgery: A randomized controlled trial

Abstract

Purpose: The study aimed at the evaluation of the impact of intravenous (IV) dexamethasone on efficacy and duration of analgesia of paravertebral block (PVB) in patients undergoing modified radical mastectomy (MRM). Patients and methods: This randomized, double-blind controlled trial included 50 patients with breast cancer scheduled for unilateral MRM. Ultrasound-guided PVB was performed in out-of-plane technique. The technique was repeated at each segment from C7 to T6. The participants were randomly allocated to one of two groups. Group BD (n=25) received IV 8 mg dexamethasone diluted with 8 mL of normal saline to reach 10 mL solution, while Group B received IV 10 mL normal saline. Top-up local infiltration analgesia into the surgical field was performed by the surgeon if needed using lidocaine 1% intraoperatively. Propofol infusion of 50–100 µg/kg/min was maintained throughout the surgery. The time to administration of the first postoperative analgesic dose, pain intensity as visual analog scale (VAS) score, number of patients who required rescue morphine analgesia, total morphine consumption, postoperative nausea and vomiting (PONV) impact scale, and the overall satisfaction of patients with pain management were measured. Results: Fifty patients were randomized and analyzed. The time to first rescue analgesic dose was significantly longer in Group DB (P<0.001). The VAS scores were significantly lower in Group DB compared to Group B up to 12 hours postoperatively. Morphine consumption was lower in Group DB compared to Group B. PONV Impact Scale score was significantly higher in Group B. Conclusion: Systemic dexamethasone increased the efficacy and duration of the single-shot multilevel PVB in breast cancer surgery. Trial registration: ISRCTN registry, study ID: ISRCTN15920148.