Comparison of costotransverse block and erector spinae plane block for perioperative analgesia in patients scheduled for modified radical mastectomy – A pilot study

Background and Aims: Fascial plane blocks have emerged as a promising element for multimodal analgesia in breast surgeries. This study aimed to compare intra-operative and post-operative opioid requirements following costotransverse block (CTB) and erector spinae plane block (ESPB) for perioperative analgesia in patients scheduled for modified radical mastectomy (MRM). Methods: Sixty patients aged 25 to 65 years scheduled for MRM were randomised to receive either CTB or ESPB with 25 ml of 0.5% bupivacaine. The primary outcome was to compare the effectiveness of these two blocks in reducing the consumption of opioids for post-operative pain relief, measured by 24-hour morphine requirement. Secondary outcomes included time required to perform the block, intra-operative haemodynamics, total intra-operative fentanyl requirement, post-operative nausea and vomiting (PONV), and any complications related to the blocks. Results: The numeric rating scale scores were comparable between the groups at all time points during the 24-hour post-operative period. The rescue analgesic requirement (morphine), median (interquartile range) was similar in the CTB group (3 [3, 3] mg) and in the ESPB group (3 [3, 3.75] mg) ( P = 1.00). The intra-operative fentanyl requirement median (interquartile range) was significantly higher in the ESPB group, 100 (100, 150) μg, than in the CTB group, 100 (100, 100) μg ( P = 0.006). Incidence of PONV was comparable between the groups. Conclusion: Both CTB and ESPB are comparable in providing post-operative analgesia for MRM patients. However, CTB likely offers better intra-operative analgesia as observed by the lower intra-operative opioid requirement.