Background: Modified radical mastectomy (MRM) is frequently associated with considerable postoperative pain, necessitating effective regional analgesic techniques. Although the thoracic paravertebral block (PVB) is regarded as the gold standard, it presents technical challenges and potential complications. The ultrasound-guided erector spinae plane block (ESPB) has emerged as a simpler and potentially safer alternative, particularly for anaesthesiology trainees. Aim: This study aims to compare the feasibility of ultrasound-guided erector spinae plane block and thoracic paravertebral block when performed by anaesthesiology residents in patients undergoing modified radical mastectomy. Methods: This prospective, randomized comparative study was conducted at a tertiary care hospital in Tamil Nadu from May 2024 to February 2025. A total of 100 patients (ASA I–II), aged 40–65 years, scheduled for MRM under general anaesthesia were randomized into two groups: ESPB (n=50) and PVB (n=50). Blocks were administered under ultrasound guidance by anaesthesia residents following the induction of anaesthesia. Primary outcomes included feasibility parameters such as ease of performance, time required, and number of needle attempts. Secondary outcomes included postoperative pain scores assessed using the visual analogue scale (VAS). Statistical analysis was conducted using SPSS, with p < 0.05 considered significant. Results: The mean time required to perform the block was significantly shorter in the ESPB group compared to the PVB group. ESPB also necessitated fewer needle guidance interventions, indicating higher technical success. Postoperative VAS scores were comparable at 4 hours; however, from 8 to 24 hours, ESPB provided significantly better analgesia than PVB (p < 0.05). Conclusion: Ultrasound-guided erector spinae plane block is easier to perform, requires less time, and provides superior prolonged postoperative analgesia compared to paravertebral block when performed by anaesthesia residents. ESPB represents a safe, effective, and feasible alternative to PVB, particularly in teaching institutions.

Erector spinae plane block, paravertebral block, modified radical mastectomy, postoperative analgesia.