Effects of Ultrasound-Guided Erector Spinae Plane Block on Early Postoperative Inflammatory and Metabolic Parameters in Patients Undergoing Breast Cancer Surgery

Background and Objectives: Surgical treatment of breast cancer is commonly associated with a pronounced inflammatory and metabolic stress response, which may adversely affect postoperative recovery. The erector spinae plane block (ESPB) is an ultrasound-guided regional anesthesia technique that has been suggested to influence perioperative stress responses through effective analgesia and reduced opioid requirements. This study aimed to evaluate the effects of ESPB on early postoperative inflammatory and metabolic parameters in patients undergoing breast cancer surgery. The present study represents a secondary exploratory analysis of a previously reported clinical cohort. The central hypothesis was that the addition of ESPB to general anesthesia (GA) would be associated with different early postoperative patterns of inflammatory and metabolic parameters compared with GA alone. Materials and Methods: This secondary exploratory analysis included 48 female patients (aged 50–65 years) scheduled for modified radical mastectomy. They were sequentially allocated in an alternating manner into two groups: one receiving only GA (n = 24) and the other GA with ESPB (n = 24). Inflammatory markers (interleukin-6, leukocyte count, neutrophil-to-lymphocyte ratio, C-reactive protein, and fibrinogen) and blood glucose levels were measured preoperatively and in the immediate postoperative period. Statistical analysis was conducted using t-tests, Mann–Whitney tests, and repeated measures ANOVA. Results: Patients who received ESPB in addition to GA had significantly lower immediate postoperative CRP levels (p < 0.001), while leukocyte and neutrophil counts showed significantly different patterns of change over time between the groups (time × group interaction: p = 0.005 and p = 0.003, respectively). While IL-6 levels did not differ significantly between the groups, immediate postoperative blood glucose levels were significantly lower in the ESPB group (p < 0.001), indicating a more favorable early postoperative glycemic profile. Conclusions: In patients undergoing breast cancer surgery, the addition of ESPB to general anesthesia was associated with different patterns of change in selected inflammatory parameters and lower blood glucose levels during the immediate postoperative period compared with general anesthesia alone. The present findings are limited to this early postoperative time point and do not establish a sustained anti-inflammatory or metabolic effect.