Intraoperative Infusion of Either Lidocaine or Dexmedetomidine on Regional Cerebral Oxygen Saturation and Postoperative Delirium in Elderly Patients Undergoing Abdominal Surgeries

This study aims to compare the effect of intraoperative infusion of either lidocaine or dexmedetomidine on the incidence of postoperative delirium (POD) in elderly patients undergoing major surgeries. It also aims to evaluate the impact of both medications on intraoperative regional cerebral oxygen saturation (rSO₂).

Postoperative delirium (POD) is a significant complication in elderly patients undergoing major surgery, with an incidence ranging from 10% to 50%, depending on patient and surgical factors. Regional cerebral oxygen saturation (rSO₂), measured using near-infrared spectroscopy (NIRS), provides a real-time, non-invasive marker of cerebral perfusion. Previous studies have demonstrated that intraoperative declines in rSO₂ are associated with an increased risk of POD. Lidocaine, an amide local anesthetic, has been shown to reduce neuroinflammation, improve microcirculation, and exert neuroprotective effects. It has been associated with low postoperative pain, reduced opioid consumption, and improved cognitive outcomes. Dexmedetomidine, an α2-adrenergic agonist, is known for its sedative, analgesic, and sympatholytic effects. It has been shown to enhance cerebral perfusion, improve rSO₂, and reduce POD incidence.