Serratus anterior plane block (posterior approach) versus erector spinae plane block in modified radical mastectomy; A randomized comparative trial

Background: Regional analgesia as Erector Spinae Plane Block (ESPB) and Serratus Anterior Plane Block (SAPB) were used successfully for the control of perioperative pain in females undergoing modified radical mastectomy (MRM). Methods: The trial included 56 females aged between 20 and 60 years old who had undergone MRM and were allocated into two groups (28 patients in each), group (I) for SAPB (posterior approach) and group (II) for ESPB. Measurements included demographic data, hemodynamic change, oxygen saturation, pain intensity by the visual analogue scale (VAS), sensory loss including axillary coverage and shoulder pain, incidence of neuropathic pain, total analgesic requirements, patient satisfaction and complications. Results: Demographic data, hemodynamic changes and oxygen saturation showed statistically insignificant differences. There were insignificant differences in the visual analogue scale (VAS) for pain at rest and on movement between the two groups on the first postoperative day (p-value >0.278 and 0.111 respectively). ESPB provided significantly more segmental sensory loss than SAPB (posterior approach) (p-value <0.031). We reported statistically insignificant differences in terms of total morphine consumption, the first request for analgesia and total local anaesthetic consumption (p-value = 0.408, 0.916 and 0.574 respectively), axillary sensory loss, inferior shoulder pain (p-value = 0.763), the incidence of neuropathic pain assessed by the Deuleur Neuropathique 4 (DN4) scale after one week and one month (p-value = 1.000 and 0.554 respectively), Neuropathic Pain Scale (NPS) score, and patient satisfaction (p-value = 0.887) between the two groups with no documented complications. Conclusion: We concluded that SAPB (posterior approach) and ESPB are safe and effective analgesic modalities for MRM with insignificant differences except for the more blocked dermatomes in the ESPB group.