Lidocaine is one of the most commonly used sodium-channel blockers in the medical armamentarium. It has long been used for its local anesthetic and anti-arrhythmic properties, and has been studied as an adjunct to general anesthesia. While lidocaine is cardio-toxic in excessive doses, the therapeutic and toxic levels are well-documented and wide, making lidocaine a drug with a favorable safety profile. Randomized clinical trials have shown perioperative lidocaine infusions to decrease postoperative pain scores, reduce postoperative opioid requirements, shortens hospital stays, improves postoperative recovery and fatigue score when administered as an adjuvant during surgery. Lidocaine has analgesic, antihypertensive, and anti-inflammatory properties. To date, no clinical trials have been conducted to establish the relationship between lidocaine infusions and postoperative recovery, particularly cognitive function, in elderly orthopedic surgery patients. It is therefore the aim of this study to evaluate the effects of lidocaine infusion on postoperative cognitive function in elderly patients having general anesthesia for orthopedic surgery, and to assess whether intraoperative lidocaine infusion decreases postoperative opioid usage and improves recovery.