Role of Opioid Free Anaesthesia in Elderly Patients Undergoing Elective Coronary Artery Bypass Graft Surgeries With Cardiopulmonary Bypass in Enhanced Recovery After Surgeries

The introduction of synthetic opioids in 1960 to general anesthesia together with sedative hypnotics and muscle relaxants allowed the appearance of the concept of multimodal balanced anesthesia. Although they help in achieving hemodynamic stability during anesthesia of open heart surgeries, their administration consequences are neither scarce nor benign to the patient. Perioperative opioids are associated with increased incidence of respiratory depression, prolonged mechanical ventilation, nausea and vomiting, prolonged sedation, Postoperative ileus (POI), urine retention, Postoperative cognitive dysfunction (POCD), immune depression and hyperalgesia (Beloeil et al., 2018). Coronary artery bypass graft surgery with cardiopulmonary bypass (CPB) is particularly vulnerable to the above-mentioned complications. Indeed, some of the side effects of this surgery overlap with the adverse effects of opioids. Postoperative pulmonary complications are observed in up to 50% of patients (Fisscher et al., 2022) and POCD or delirium in 4-54% according to studies (Bhushan et al., 2021). Whereas major gastrointestinal complications are estimated to occur in around 3% of patients, essentially acute pancreatitis, postoperative ileus (Marsoner et al., 2019). Opioid-free anesthesia (OFA) strategies have emerged to avoid intraoperative opioid use. It is based on the fact that a sympathetic reaction evidenced by hemodynamic changes in an anesthetised patient does not systematically reflect pain. In addition, a sleeping patient will not recall pain, while hormonal stress and sympathetic and inflammatory reactions can be controlled by therapeutic classes