Efficacy of OSTAP, ESP block, trocar site local anesthetic injection in elective laparoscopic cholecystectomy: A randomized controlled trial.

BACKGROUND

Effective postoperative pain control remains a clinical challenge in laparoscopic cholecystectomy (LC). Regional anesthesia techniques such as the erector spinae plane (ESP) block and the oblique subcostal transversus abdominis plane (OSTAP) block have gained popularity as potential alternatives to traditional analgesic methods. This double-blind, randomized controlled trial aimed to compare the analgesic efficacy of ESP block, OSTAP block, and trocar site local anesthetic (LA) infiltration in terms of postoperative pain scores and opioid consumption in patients undergoing LC.

METHODS

A total of 100 patients were equally randomized into 4 groups: ESP block (Group E), OSTAP block (Group T), trocar site LA infiltration (Group L), and a control group (Group C) receiving multimodal analgesia. ESP and OSTAP blocks were applied unilaterally prior to surgery. All patients were followed for 24 hours postoperatively. Pain intensity was evaluated using the visual analog scale (VAS), and cumulative tramadol consumption, additional analgesic requirements, nausea-vomiting scores, and incidence of shoulder pain were recorded. Data analysis was performed using SPSS, with Bonferroni correction applied for multiple comparisons.

RESULTS

VAS scores at all-time points were significantly lower in Groups E and L compared to Group C (P < .05). Although Group T also showed lower scores than Group C, this difference was not statistically significant after correction. Total tramadol consumption was significantly lower in Group E (112.2 ± 105.4 mg) and Group T (163.6 ± 127.1 mg) compared to Group C (281.8 ± 144.8 mg) and Group L (291.8 ± 131.6 mg; P < .001). Additional analgesic requirement rates were significantly lower in Groups E, T, and L than in Group C (P < .05). No adverse events such as LA toxicity or allergic reactions were observed. Nausea-vomiting scores and shoulder pain incidence were comparable across all groups.

CONCLUSION

Both ESP and OSTAP blocks effectively reduced postoperative opioid requirements, with the ESP block demonstrating greater efficacy in terms of pain control. These findings support the use of unilateral ESP and OSTAP blocks as effective components of multimodal analgesia protocols in LC.