Efficacy and safety of ultrasound-guided serratus anterior plane block with different doses of dexmedetomidine for patients undergoing modified radical mastectomy: A randomized controlled trial

Background: Ultrasound-guided serratus anterior plane block (USG-SAPB) has been used for pain management of patients undergoing modified radical mastectomy (MRM), but evidence supporting the adjuvant analgesic benefits is limited. We explored the efficacy and safety of preemptive use of different concentrations of dexmedetomidine and ropivacaine in USG-SAPB for patients undergoing MRM. Patients and methods: Ninety-five female patients were randomly allocated to RD1 and RD2 groups. USG-SAPB was performed before anesthesia induction. Consumption of sufentanil, postoperative pain scores, and level of sedation were recorded 1–72 h postoperatively. Intraoperative hemodynamics, PACU length of stay, incidence of moderate-severe pain, one-time puncture success, block procedure time, time to first rescue analgesia, satisfaction scores of patients and surgeons, hospital length of stay, adverse events, the prevalence of chronic pain, and quality of postoperative functional recovery were recorded. Results: : Dynamic VAS was significantly lower at 4, 8, and 12 h after surgery and sufentanil need was significantly lower at 4, 8, 12, 24, and 48 h after surgery in the RD2 group (P<0.05). The incidence of moderate-severe pain was significantly lower in the RD2 group (P<0.05). Time to first rescue analgesia was significantly longer in the RD2 group (P=0.047). Consumption of propofol, remifentanil, dexmedetomidine, use of vasoactive agents, and PACU length of stay (LOS) were significantly reduced in RD2 patients (P<0.05). There were no significant differences between the two groups with respect to procedural variables or satisfaction scores of patients and surgeons, and/or postoperative complications. The hospital LOS, global QoR-40, and prevalence of chronic pain were comparable. Conclusions: : Use of 1 μg/kg dexmedetomidine and ropivacaine in USG-SAPB can provide superior postoperative analgesia for patients undergoing MRM without additional adverse effects, and result in similar quality of postoperative functional recovery and prevalence of chronic pain.