Effect of erector spinae plane block as a part of combined anesthesia on the incidence of postmastectomy pain syndrome

The incidence of postmastectomy pain syndrome (PMPS) after mastectomy ranges from 20% to 60%. Interfascial blockade of the erector spinae muscle (ESPB) can reduce pain in early postoperative period after total mastectomy and possibly reduce the incidence of PMPS. Objective. To evaluate the effect of ESPB as a part of combined anesthesia on the incidence of PMPS after total mastectomy. Material and methods. A pilot prospective single-center randomized study included 88 patients divided into two groups: the study group — ESPB in addition to combined general anesthesia (CGA) (n=23), the control group (n=65) — CGA alone. Postoperative pain was assessed using the visual analogue scale (VAS) after awakening, 2 and 24 hours after surgery. The painDETECT questionnaire was used to estimate neuropathic component of pain 3 months later. Results. ESPB was followed by significantly lower VAS scores in 1, 2 and 24 hours after surgery, as well as lower PainDetect scores 3 months after surgery. The risk of postoperative PMPS was significantly lower in the study group by 10.7 (95% CI 1.3; 86.3) times. Conclusion. ESPB provides better early postoperative analgesia compared to standard intraoperative and postoperative analgesia. This approach significantly reduces the incidence of PMPS after total mastectomy by 10.7 (95% CI 1.3; 86.3) times.