Application of a new serratus anterior plane block in modified radical mastectomy under ultrasound guidance: A prospective, randomized controlled trial

Post-operative pain is a significant concern following modified radical mastectomy in breast cancer patients. The serratus anterior plane block has recently been described as an effective technique for post-operative analgesia of modified radical mastectomy. The purpose of this study was to evaluate the analgesic efficacy and safety of a new serratus anterior plane (SAP) block for post-operative pain of mastectomy.A randomized controlled trial.Single university teaching hospital, from October 2019 to April 2020.Eighty-seven female breast cancer patients aged 30-81 years scheduled for unilateral modified radical mastectomy.Participants were randomly allocated to receive either general anesthesia plus SAP block (SAP block group, n = 43) or general anesthesia alone (Control group, n = 44). A single injection of 20 ml of 0.5% ropivacaine was administered into fascial plane between the pectoralis major and the serratus anterior in SAP block group. In the Control group, no block intervention was applied.The primary outcome measure of the study was the VAS pain scores at different time-points (1, 6, 12, 24, 48 h) after modified radical mastectomy whereas the secondary outcome measures were the consumption of opioid analgesics.Breast cancer patients in SAP block group had lower VAS pain scores compared with the Control group during the early post-operative period (1 h and 6 h after modified radical mastectomy), both at rest and with movement. In addition, the consumption of propofol was similar in two groups (P = 0.406), and the consumption of sufentanil and remifentanil in SAP block group were significantly lower than that of Control group (P = 0.000 and P = 0.000, respectively).SAP block significantly attenuated post-operative pain and decreased opioids consumption in breast cancer patients undergoing modified radical mastectomy.This trial is registered in the Chinese Clinical Trial Registry (ChiCTR1900026989).