Comparison of ropivacaine alone versus dexmedetomidine or ketamine as an adjuvant for pectoral type II nerve blocks in patients undergoing mastectomy - A randomized controlled trial.

Background and aims: This study evaluates the analgesic efficacy of ketamine and dexmedetomidine as an adjuvant with ropivacaine 0.2% in pectoral nerve type II block (PECS-II) in modified radical mastectomy. The primary outcome of the study was the time to first rescue analgesia postoperatively. The secondary outcomes were intraoperative and postoperative opioid consumption and postoperative pain on the numerical rating scale.

Material and methods: Seventy-five adult female patients who underwent a modified radical mastectomy participated in this prospective, randomized, double-blinded clinical trial. The patients received 30 ml of 0.2% ropivacaine with or without adjuvants by the ultrasound-guided PECS-II block. Group R (n = 25) received ropivacaine 0.2% without adjuvants. Group RD (n = 25) and group RK (n = 25) received dexmedetomidine 1μg/kg and ketamine 1 mg/kg, respectively, along with ropivacaine 0.2%.

Results: Duration of analgesia determined by time to first rescue analgesia was longer in group RD (18.42 ± 02.15 h) compared to group RK (15.91 ± 03.21 h) and group R (14.64 ± 02.85 h), which was statistically significant (P < 0.001). Fentanyl consumption in the first 48 h after surgery was significantly less in the dexmedetomidine group compared to other groups.

Conclusion: We conclude that dexmedetomidine with 0.2% ropivacaine in the PECS-II block provides better postoperative analgesia and has less sedative effects than ketamine with 0.2% ropivacaine.