Study compares ESP Block with MTP Block for Postoperative Pain in Modified Radical Mastectomy

Modified radical mastectomy (MRM) is linked to postoperative pain, which, if not effectively managed, may progress to chronic pain in nearly 55% of instances. Recent study compared the effectiveness of the erector spinae plane (ESP) block and the midpoint transverse process to pleura (MTP) block for postoperative analgesia in patients undergoing modified radical mastectomy (MRM). The study was a double-blinded, randomized controlled trial conducted at a tertiary healthcare institute in India.

Patient Selection and Method

The researchers included 66 patients assigned ASA physical status I-II, aged 18-75 years, who were scheduled for MRM. Patients were randomly allocated to receive either the ESP block or the MTP block at the T3 or T4 level on the operative side, with 15 ml of 0.5% ropivacaine. Pain was assessed using the Visual Analogue Scale (VAS) for 24 hours postoperatively. The number of patients needing rescue analgesia, the total amount of rescue analgesics consumed, and patient satisfaction scores were also compared between the two groups.

Results and Comparison

The results showed no difference in VAS scores between the two groups during the initial 2 hours. However, from the 3rd hour onwards, the ESP group had significantly lower VAS scores compared to the MTP group when followed for the next 24 hours. Eight patients in the MTP group and 3 in the ESP group required rescue analgesia in the 24-hour period. The mean dose of rescue analgesia was also significantly lower in the ESP group. Patient satisfaction scores were higher in the ESP group compared to the MTP group.

Conclusion and Limitations

The researchers concluded that the ESP block is more effective than the MTP block in providing postoperative analgesia in patients undergoing MRM. The wider craniocaudal spread of local anesthetic in the ESP block likely contributed to its superior analgesic efficacy compared to the more variable spread seen with the MTP block. The study was limited by the short 24-hour follow-up period, lack of immediate assessment of block distribution and success, and a relatively small sample size. Further larger studies are needed to confirm these findings.

Key Points

The 3 key points from the research paper are:

1. The study compared the effectiveness of the erector spinae plane (ESP) block and the midpoint transverse process to pleura (MTP) block for postoperative analgesia in patients undergoing modified radical mastectomy (MRM).

2. The results showed that the ESP group had significantly lower visual analogue scale (VAS) pain scores compared to the MTP group from the 3rd hour onwards for the 24-hour period, with fewer patients requiring rescue analgesia and a lower mean dose of rescue analgesia in the ESP group. Patient satisfaction scores were also higher in the ESP group.

3. The researchers concluded that the ESP block is more effective than the MTP block in providing postoperative analgesia for patients undergoing MRM, likely due to the wider craniocaudal spread of local anesthetic in the ESP block. However, the study was limited by the short follow-up period, lack of immediate assessment of block distribution and success, and a small sample size, requiring further larger studies to confirm the findings.

Reference –

Sethi P, Kaur M, Bhatia PK, Goyal S, Sharma A, Roy S, et al. Comparison of midpoint transverse process to pleura (MTP) block and erector spinae plane block (ESP) for postoperative analgesia in modified radical mastectomy patients: A double‑blinded, randomized control trial. J Anaesthesiol Clin Pharmacol 2024;40:344‑50.