Opioid-Sparing Effects of Peripheral Nerve Blocks in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis

BACKGROUND Kidney transplantation (KT) is frequently associated with substantial postoperative pain, while opioid use in these patients increases the risk of adverse outcomes. Peripheral nerve blocks (PNBs) have been proposed as opioid-sparing strategies; however, evidence in kidney transplant recipients remains inconsistent, likely due to heterogeneity in block techniques, variability in perioperative analgesic regimens, and differences in study design and methodological rigor. This systematic review and meta-analysis aimed to evaluate the impact of PNBs on postoperative analgesia in kidney transplant recipients. MATERIAL AND METHODS A systematic search of PubMed, EMBASE, the Cochrane Library, and Web of Science was conducted through April 2025 following the Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies reporting 24-h postoperative opioid consumption in adult kidney transplant recipients were included. The primary outcome was cumulative opioid use within 24 hours after surgery, expressed as intravenous morphine or fentanyl. RESULTS Twelve studies met the inclusion criteria, of which 10 contributed to the quantitative synthesis. Pooled analysis showed that PNBs significantly reduced 24-h morphine consumption compared with control analgesia (pooled mean difference=-16.20 mg of intravenous morphine equivalents, 95% confidence interval -24.66 to -7.74; P=0.0002). Heterogeneity was high (I²=99%), but no study reported higher opioid use or increased adverse events in the PNB groups. CONCLUSIONS PNBs appear to be an effective opioid-sparing adjunct for postoperative analgesia in kidney transplant recipients. However, the available evidence remains limited, and further well-designed comparative trials are needed to define their role within multimodal analgesic strategies in this population.