Effects of fentanyl and dexmedetomidine as adjuvants to bupivacaine in paravertebral block for postoperative analgesia in patients undergoing modified radical mastectomy: A prospective randomised double-blind study

Background and Aims: Paravertebral block (PVB) is an established method, indicated for postoperative analgesia after modified radical mastectomy (MRM). Although many additives to bupivacaine in PVB have been tried to prolong the analgesia in postoperative period, no additive has been found without any adverse effects. We have compared the duration of analgesia in PVB using adjuvants like dexmedetomidine and fentanyl with bupivacaine after MRM. Methods: A total of 60 female patients enroled for MRM were divided into two groups of 30 patients each. Group BF received PVB with 20 ml bupivacaine 0.25% with fentanyl 1 μg/kg and group BD received 20 ml bupivacaine 0.25% with dexmedetomidine 1 μg/kg for PVB. After confirming successful PVB, surgery was done under general anaesthesia. Time for first rescue analgesic request was the primary outcome of the study. The secondary outcome was comparison of visual analogue scale scores for pain and total analgesic consumption. Side effects like sedation, nausea, vomiting, bradycardia and hypotension in the postoperative period till 24 h were also assessed. Results: The time for first rescue analgesic request was 6.32 ± 1.75 h in the BD group contrary to 3.94 ± 2.12 h in group BF (P < 0.05). Total paracetamol consumed as rescue analgesia in the first 24 h of postoperative period was remarkably reduced in group BD (1.7 ± 0.94 gm) in contrary to group BF (2.6 ± 0.98 gm) (P < 0.05). There was no significant difference in the incidence of complications between the groups. Conclusion: Dexmedetomidine provides prolonged postoperative analgesia compared with fentanyl when used as an adjuvant to bupivacaine in PVB after MRM