Background: Multimodal analgesia that includes pharmacotherapy and regional anesthetic techniques such as erector spinae plane block (ESPB), is recommended for the management of post-mastectomy pain
Methods: A retrospective analysis of 75 patients' records who had modified unilateral radical mastectomy where the initial anesthetic plan was ESPB with general anesthesia were reviewed. According to the patient's position during the ESPB, they were assigned into three groups: Group I (sitting position), Group II (lateral decubitus), and Group III (prone position). The endpoints were the dermatomal sensory block, visual analog scale (VAS) for pain, the time to the first request for postoperative analgesia, opioid consumption, neuropathic pain & complications, and anesthesiologist satisfaction.
Results: More sensory block coverage was detected in the mid-axillary and mid-clavicular lines in group I compared with groups II and III (p-value < 0.001). The VAS for pain did not differ significantly among the studied groups over 16 hours postoperatively. However, it decreased significantly in group I compared to the other groups at 20 and 24 hours postoperatively. The percentage of patients who requested morphine analgesia, the time for the first request of rescue opioid, and the total dose of analgesic requirements were comparable. There was insignificant variation regarding the anesthesiologist's satisfaction with the ease of the block and the incidence of neuropathic pain.
Conclusion: ESPB in the sitting position resulted in more dermatomal sensory block and prolonged analgesia. However, compared to the prone or lateral positions, it did not significantly reduce analgesic requirement or the development of neuropathic pain.