Effect of Ultrasound Guided Thoracic Erector Spinae Plane Block or Modified Pectoral Fascial Plane Block on the Postoperative Analgesia after Modified Radical Mastectomy: A Randomized Controlled Study

Background: The most common cancer in women worldwide is the breast cancer which needs surgical intervention in large number of cases. The current randomized controlled study aimed to evaluate the postoperative analgesic effect of ultrasound-guided Erector Spinae plane block and ultrasound-guided modified PECs block for female patients subjected to modified radical mastectomy surgeries (MRM).

Methods: This prospective randomized controlled study was carried out in the Anasthesia Department at the Faculty of Medicine Tanta University Female patients aged between 21 and 64 years with American Society of Anesthesiology (ASA) physical status II-III who were scheduled for unilateral Modified radical mastectomy were included. Patients had randomly classified us into three equal groups: 20 patients in each group. Group I: Control group (n=20): Patients of this group did not receive any nerve block, Group II: Erector Spinae plane Block (ESB) (n=20): Patients of this group received ultrasound guided erector spinae plane block with injection of (20 ml) of plain bupivacaine 0.25% injected beneath the erector spinae muscle sheath at the level of the fourth thoracic segment (T4) after induction of general anathesia, Group III: US-modified PEC block (n=20): Patients of this group received ultrasound guided modified PEC block with injection of (10 ml) of plain bupivacaine 0.25% injected between the serratus anterior and pectoralis minor muscle (PECs2)and (20ml)of the same solution between pectoralis major muscle and pectoralis minor muscle after induction of general anathesia.

Results: NRS showed a statistically significant decrease at T2 in group III compared to group II. (P value < 0.05). Comparison between the three groups in intra-operative and post-operative MAP showed statistically significant difference between groups throughout intraoperative and postoperative durations. MAP showed statistically significant decrease in groups II and III compared to group I (P value = 0.001). there was also a statistically significant difference between group II and group III in T0, T15, T45, T60, T00, T2 and T12 in favor of group III. Comparison between the three groups in intra-operative and post-operative HR showed statistically significant difference between groups throughout intraoperative and postoperative duration. HR showed statistically significant decrease in groups II and III compared to group I (P value = 0.001). There was also a statistically different decrease in HR between group II and group III in favor of group III (modified PECS group).

Conclusions: Both ESB and PECSII blocks provided adequate analgesia as indicated by lowering doses of intraoperative fentanyl consumption, longer duration of postoperative analgesia, lower doses of post-operative morphine consumption compared to general anesthesia alone.