The Impact of Ultrasound-Guided Regional Anesthesia on Postoperative Pain Control and Opioid Reduction in Adult Surgical Patients: A Systematic Review

Abstract

Background
Postoperative pain remains a major challenge in surgical care, often leading to delayed recovery and increased opioid-related adverse effects. Although systemic opioids have traditionally been central to pain management, concerns about dependence and side effects have driven interest in opioid-sparing strategies. Ultrasound-guided regional anesthesia (UGRA) offers targeted analgesia with improved precision, yet variability in reported effectiveness across procedures warrants a systematic evaluation.

Methods
This systematic review followed PRISMA guidelines to evaluate the impact of UGRA on postoperative pain control and opioid reduction in adult surgical patients. A comprehensive literature search was conducted in PubMed/MEDLINE, Embase, Cochrane CENTRAL, and Web of Science. Eligible studies included randomized controlled trials, cohort studies, and controlled clinical studies comparing UGRA with conventional analgesia, systemic opioids, or no block. Primary outcomes were postoperative pain intensity (validated scales) and opioid consumption. Risk of bias was assessed using the Cochrane Risk of Bias tool and Newcastle–Ottawa Scale. A narrative synthesis was performed.

Results
Six primary studies (five RCTs and one network meta-analysis; total N = 1,581 patients) across cardiac, thoracic, orthopedic, and maxillofacial surgeries met inclusion criteria. UGRA consistently reduced postoperative opioid consumption compared to controls: intravenous fentanyl decreased by 47.4% (p < 0.0001), rescue morphine by 68.2% (p < 0.001), and oral morphine equivalents by 44.2% (p = 0.023). Pain scores at rest and during coughing were significantly lower in block groups during the first 12–18 hours (p < 0.05 to p < 0.0001), with dynamic pain reduced by 3.3 units on VAS (p < 0.0001). UGRA also reduced postoperative nausea by up to 50%, shortened extubation time (108.5 vs. 206.3 minutes; p < 0.0001), and decreased ICU length of stay by 1.1 days. No major complications (LAST, nerve injury, pneumothorax) were reported.

Conclusion
Ultrasound-guided regional anesthesia significantly improves postoperative pain control, reduces opioid consumption and opioid-related adverse effects, and enhances early respiratory recovery across multiple adult surgical populations. These findings support integrating UGRA into multimodal perioperative analgesic protocols as an effective and safe opioid-sparing strategy. Further large-scale, standardized trials are warranted to optimize technique selection and prolong analgesic duration.