Perioperative Lidocaine and Ketamine in Abdominal Surgery

Exclusion Criteria

• •1\. Planned postoperative mechanical ventilation
• •2\. Planned regional anesthesia/analgesia
• •3\. Perioperative gabapentin, magnesium, or nitrous oxide use
• •4\. Pregnancy or breastfeeding
• •5\. Morbid obesity (BMI ≥ 35 kg/m2)
• •6\. American Society of Anesthesiologists (ASA) physical status IV-V
• •7\. Allergy to study medications
• •8\. Contraindication to lidocaine (severe cardiac arrhythmia)
• •9\. Contraindication to ketamine (psychiatric disorder, substance abuse, uncontrolled hypertension, pulmonary hypertension, increased intracranial or intraocular pressure, use of monoamine oxidase inhibitors)
• •10\. Chronic preoperative opioid use (≥ 90 morphine mg equivalents per day for \> 3 months)
• •11\. Significant preoperative hepatic dysfunction (alanine aminotransferase or aspartate aminotransferase levels \> 5 times normal) or planned liver transplantation
• •12\. Preoperative cardiac failure (left ventricular ejection fraction ≤ 40%)
• •13\. Unable to communicate or comprehend study instructions