The impact of combining regional nerve block with general anesthesia on cognitive function in patients undergoing elbow joint release surgery: a randomized controlled trial.

Background and aim: Regional nerve block, as an anesthetic technique, can enhance postoperative recovery for patients. Postoperative cognitive dysfunction (POCD) remains a critical concern for patients undergoing elbow joint release surgery. This randomized controlled trial evaluated whether combining regional nerve block (RNB) with general anesthesia (GA) improves cognitive outcomes compared to GA alone.

Methods: A single-center and single-blind (outcome assessors and analysts blinded) observation study. Seventy-four patients (ASA I-II, aged 18-65 years, BMI < 26 kg/m2) undergoing elbow joint release surgery were randomly assigned to either a control group (GA alone) or an observation group (Ultrasound-guided brachial plexus block: 20 mL 0.375% ropivacaine + GA). Primary outcome was MMSE scores on Pre-op D 1 (preoperative day 1), POD 1 (postoperative day 1), and POD 3 (postoperative day 3). Secondary outcomes included awakening time, extubation time, VAS scores at 1, 6, 12 hours after extubation and hemodynamic parameters at different time points.

Results: The MMSE scores in the observation group were significantly higher than those in the control group both on the POD 1 (23.06 ± 1.01 vs 20.50 ± 0.51, mean difference 2.56 [95% CI 2.18 to 2.93]; P < 0.001) and POD 3 (25.56 ± 0.51 vs 23.36 ± 0.49, mean difference 2.19 [95% CI 1.96 to 2.43]; P < 0.001). The postoperative awakening time (3.50 ± 0.56 vs 11.83 ± 1.00 min, mean difference -8.33 [95% CI -8.71 to -7.95]; p < 0.001) and extubation time (3.50 ± 0.56 vs 13.08 ± 0.84 min, mean difference -9.58 [95% CI -9.92 to -9.25]; p < 0.001) in the observation group were significantly shorter than those in the control group. Furthermore, Visual analogue scale (VAS) scores in the observation group were lower than those in the control group at 1 hour (1.28 ± 0.61 vs 4.92 ± 0.77, mean difference -3.64 [95% CI -3.97 to -3.31]; p < 0.001), 6 hours (1.36 ± 0.54 vs 5.67 ± 0.68, mean difference -4.31 [95% CI -4.59 to -4.02]; p < 0.001), and 12 hours post-extubation(3.44 ± 0.50 vs 7.67 ± 0.48, mean difference -4.22 [95% CI -4.45 to -3.99]; p < 0.001). Hemodynamic stability was superior in the observation group across perioperative phases.

Conclusions: Combining RNB with GA preserves postoperative cognitive function, accelerates recovery, and enhances analgesia in elbow joint release surgery. These findings support RNB as an adjunct to GA to mitigate POCD.