Postoperative Cognitive Dysfunction and Analgesic Outcomes in Cardiac Surgery

OBJECTIVE: Cardiac surgery frequently induces moderate to severe postoperative pain, which impedes recovery and elevates the risk of opioid dependence and postoperative cognitive dysfunction. This review aims to outline peripheral nerve block approaches in cardiac surgery and examine their analgesic efficacy and potential relationship with postoperative cognitive dysfunction. MATERIALS AND METHODS: A comprehensive literature search was performed using the electronic databases PubMed, EMBASE, and Google Scholar for publications up to September 2025. Search terms included regional anesthesia, nerve block, pain management, delirium, cognitive dysfunction, and cardiac surgery. The retrieved literature, including clinical reviews, basic research, clinical trials, and guidelines, was screened and prioritized based on thematic relevance and the strength of clinical evidence. The available evidence was synthesized into a narrative review. RESULTS: The evidence suggests that nerve blocks are an effective component of a multimodal analgesic strategy, significantly reducing postoperative opioid consumption and attenuating neuroinflammatory responses such as microglial activation. However, they have not been conclusively shown to reduce the incidence of postoperative cognitive dysfunction. Current implementation faces challenges including a lack of technique standardization and the need to adapt to heterogeneous surgical anatomies. DISCUSSION: Nerve blocks are valuable for opioid-sparing analgesia and may modulate neuroinflammation, but their role in preventing postoperative cognitive dysfunction remains unproven. Future efforts should focus on standardizing protocols and conducting mechanistic studies to clarify the relationship between nerve blocks, neuroinflammatory modulation, and long-term neurological outcomes.