The effect of ultrasound-guided transversus abdominis plane block on postoperative inflammatory markers and analgesic requirements in laparoscopic cholecystectomy: a retrospective comparative study

INTRODUCTION: Ultrasound-guided bilateral transversus abdominis plane (TAP) block is widely used for post-operative analgesia in laparoscopic cholecystectomy (LC). Its potential immunomodulatory effects on systemic inflammatory markers remain poorly characterized. This study aimed to evaluate the effect of TAP block on the postoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and C-reactive protein (CRP) levels, along with key clinical outcomes.
METHODS: This single-center retrospective comparative study included 100 patients who underwent elective LC under general anesthesia between October 2022 and October 2025. Following screening of 138 consecutive records and exclusion of 38 patients, participants were allocated to the TAP group (n=51; ultrasound-guided bilateral TAP block with 20 mL of 0.25% bupivacaine per side, administered at the conclusion of surgery) or the control group (n=49; standard care alone). NLR, PLR, and CRP were measured preoperatively and at 24 hours postoperatively. Clinical outcomes included 24-hour opioid consumption, VAS pain scores, complication rates, and length of hospital stay. Given the retrospective and exploratory nature of the study, a formal primary outcome was not prespecified.
RESULTS: Baseline characteristics were comparable between the groups. Postoperative NLR (3.58 vs. 4.39; p<0.001), PLR (168.90 vs. 220.60; p<0.001), and CRP levels (32.58 vs. 44.72 mg/L; p<0.001) were all significantly lower in the TAP group. Changes in all three markers were also significantly attenuated. Twenty-four-hour opioid consumption (p=0.002) and VAS pain scores (p=0.006) were significantly lower in the TAP group. Complication rates and length of hospital stay did not differ significantly between the groups.
DISCUSSION AND CONCLUSION: Ultrasound-guided bilateral TAP block performed at the conclusion of LC significantly attenuated postoperative systemic inflammation, as reflected by lower NLR, PLR, and CRP levels, while also reducing opioid requirements and pain scores. These findings support the inclusion of TAP block in multimodal perioperative analgesic protocols and suggest a potential immunomodulatory role that warrants confirmation in prospective randomized trials.

Keywords: Inflammatory markers, laparoscopic cholecystectomy, neutrophil-to-lymphocyte ratio, postoperative analgesia, transversus abdominis plane block