Opioid Free Anesthesia-Analgesia Strategy and Surgical Stress in Elective Open Abdominal Aortic Aneurysm Repair

Open Abdominal Aortic Aneurysm (AAA) repair is a high-risk surgical procedure accompanied by intense endocrine and metabolic responses to surgical stress, with subsequent activation of the inflammatory cascade, cytokine and acute-phase protein release, and bone marrow activation. There is a proven correlation of surgical stress, which patients undergoing open AAA repair are subjected to, with patient outcome, morbidity/mortality, intensive care unit stay and overall length of stay. Modern general anesthetic techniques have been revised and rely on perioperative multimodal anesthetic and analgesic strategies for improved overall patient outcome. Based on this context of a multimodal anesthetic technique and having taken into consideration the international "opioid-crisis" epidemic, an Opioid Free Anesthesia-Analgesia (OFA-A) strategy started to emerge. It is based on the administration of a variety of anesthetic/analgesic agents with different mechanisms of action, including immunomodulating and anti-inflammatory effects. Our basic hypothesis is that the implementation of a perioperative multimodal OFA-A strategy, involving the administration of pregabalin, ketamine, dexmedetomidine, lidocaine, dexamethasone, dexketoprofen, paracetamol and magnesium sulphate, will lead to attenuation of surgical stress response compared to a conventional Opioid-Based Anesthesia-Analgesia (OBA-A) strategy. Furthermore, the anticipated attenuation of the inflammatory response, is pressumed to be associated with equal or improved analgesia, compared to a perioperative OBA-A technique.

Inclusion Criteria: 1. Patient Consent 2. Age between 40 and 85 years old 3. Patients undergoing Elective Open Abdominal Aortic Infrarenal Aneurysm Repair Exclusion Criteria: 1. Immunocompromised patients 2. Patients with active infection 3. Reoperation on the aorta 4. Inflammatory bowel Disease 5. Malignancy 6. Chronic Inflammatory conditions (e.g. Rheymatoid arthritis, Psoriatic arthritis) 7. Chronic corticosteroid or immunosuppressive drug use 8. Intraoperative transfusion with \>2 units of packed Red Blood Cells