A Randomized Trial Comparing Ultrasound Guided Modified Pectoral Block Versus Erector Spinae Block for Post Mastectomy Pain Management: A Comparative Analysis.
Background: The modified pectoral nerve (PECS) block is an established technique for providing surgical anesthesia and postoperative analgesia during breast surgery. The erector spinae plane block (ESP), has also been demonstrated to provide extensive multidermatomal sensory block. Our study compared the efficacy and safety of both these USG guided blocks for postoperative analgesia after Modified Radical Mastectomy (MRM).
Methods: 80 adult female patients (ASA grades I and II) undergoing MRM were randomly allocated into 2 groups. Group P received modified PECS block, whereas group E received ESP block using same volume and concentration of 0.375% levobupivacaine (30 mL) after induction of anaesthesia. Fentanyl was used for postoperative pain relief via patient-controlled analgesia (PCA) pumps which was set with fentanyl boluses of 25 mcg, time out interval at 15 minutes and no basal infusion.
Results: The quality of analgesia was significantly better in patients receiving modified PECS block compared with ESP block. Total fentanyl consumed at the end of 24 hrs was significantly lesser in group P (160.85 ± 50.6 mcg) as compared to group E. (235.37 ± 88.42 mcg) (p < .001). At 24 hours postoperatively, mean NRS scores in group P were significantly lower than group E (1.18 ± 1.13 vs. 2.65 ± 0.98) (p < .001). Patients who received modified PECS block had better pain relief and sleep at night compared to group E (p < .001) which was assessed via a Likert scale questionnaire. Interestingly enough, the ease of both abduction and adduction of arm was found to be significantly better in group E as compared to group P at 12 hours (p = .001) and 24 hours (p = .005) postoperatively.
Conclusions: We found that while the modified PECS block offered better postoperative pain relief, the ESP block facilitated physiotherapy, although this advantage was achieved at the cost of less effective pain management. Both blocks showed no adverse effects.