Role of erector spinae plane block versus paravertebral block in postoperative pain management of mastectomy.

Objective: To determine the role of erector spinae plane block versus paravertebral block by finding the time to need the first rescue analgesia in postoperative pain management of Mastectomy. Study Design: Randomized Controlled Trial. Setting: Department of Anesthesia, Fauji Foundation Hospital Rawalpindi. Period: October 2024 to March 2025. Methods: A total of 220 females (aged 18-65 years) undergoing unilateral modified radical mastectomy with axillary dissection were randomly assigned (1:1) to receive either erector spinae plane block (Group ESPB) or paravertebral block (Group PVB). Under ultrasound guidance at T4-T5, patients in Group ESPB received 20-25mL of 0.25%-0.375% bupivacaine with epinephrine into the erector spinae plane, while patients in Group PVB received the same solution injected into the paravertebral space at multiple levels. The primary outcome was time to first rescue analgesia (triggered at pain score ≥4 on Visual analogue scale 0-10). Secondary outcomes included 24-hour total rescue analgesia consumption, pain scores at 8, 12, and 24 hours. A p-value <0.05, established the statistical significance. Results: The results of primary outcomes established no significant difference between the Group ESPB and Group PVB in terms of time to need first recue analgesia (5.95±0.63 hours Vs 6.11±0.66 hours respectively, p=0.07). Total morphine consumption was comparable between the two groups (7.1±1.61 mg vs. 7.05 ± 1.64 mg, p=0.82). Higher pain scores was observed at 8 hours in the ESPB group compared to Group PVB (6.1 ± 0.88 vs. 5.83 ± 0.78, p=0.02), with no differences at 12 and 24h. Conclusion: Both techniques showed similar time to first rescue analgesia after mastectomy and total morphine use during 24 hours. Paravertebral block provided better early pain control at 8h; analgesia was, however, comparable beyond 12h.