EFFECTIVENESS OF RHOMBOID INTERCOSTAL AND SUB-SERRATUS (RISS) PLANE BLOCK REGIONAL ANESTHESIA AS ADJUVANT ANALGESIA IN MANAGEMENT OF POST-OPERATIVE PAIN IN PATIENTS UNDERGOING MASTECTOMY SURGERY

Background: Postoperative pain after mastectomy often decreases patients' quality of life and requires effective pain management. The RISS block (Rhomboid Intercostal and Sub-Serratus) is an alternative technique that can reduce pain and opioid requirements after surgery.
Methods: This study is a single-blind randomized clinical trial involving 40 mastectomy patients, divided into two groups: one group received general anesthesia with the RISS block, and the other group received only general anesthesia. Primary outcomes measured included opioid consumption in the first 24 hours postoperatively, pain intensity using the NRS scale, and the time to first use of PCA analgesics.
Results: The group receiving the RISS block showed a significant reduction in opioid consumption (20 ± 20 mcg vs. 100 ± 40 mcg, p < 0.05), lower pain intensity at hours 1, 3, 6, 12, and 24 (p < 0.05), and a longer time to first use of PCA (8 ± 18 hours vs. 3 ± 2 hours, p < 0.05).
Conclusion: The RISS block is effective in reducing opioid requirements and controlling postoperative pain after mastectomy. This technique can be a safe and efficient option in postoperative pain management.