The Effects of Total Intravenous and Inhalation Anesthesia Maintenance on Tissue Oxygenation in Coronary Artery Bypass Graft Surgery

A pressing issue in anesthesiology involves developing an understanding of the non-anesthetic effects of the medications typically used in intravenous and inhalation anesthesia methods. Few studies describe the effects of both intravenous and inhalational anesthetics on regional tissue perfusion is described under stable anesthetic conditions. There is the issue of whether inhalational anesthetics compromise regional tissue perfusion even though systemic parameters are within normal ranges. It is still debated how these effects may be different under pathophysiological conditions, such as cardiac surgery.

Maintaining tissue perfusion and oxygenation is the cornerstone of therapy for patients with cardiac disease. An imbalance in oxygen delivery and tissue oxygen consumption leads to anaerobic metabolism, cellular injury, and organ dysfunction, and is associated with poor outcomes. Consequently, monitoring tissue oxygen delivery and consumption status is of paramount importance in cardiac surgery patients. Routinely used monitors in intraoperative settings such as pulse oximetry, blood pressures, hemoglobin saturation levels, lactate, acid-base status, and central venous oxygen saturation levels all reflect tissue metabolism. Near-infrared spectroscopy (NIRS) is a non-invasive optical technique that can be used to continuously monitor tissue oxygen delivery and oxygen consumption status. Cerebral autoregulation can blunt the effect of impaired systemic oxygen delivery. Thus, cerebral NIRS may be a good predictor of neurological outcomes, but skeletal muscle NIRS serves as a follow-up indicator of many other postoperative complications due to impaired perfusion and oxygenation. Therefore, both cerebral and somatic monitoring may contribute to a more complete evaluation of hemodynamic competence. Obtaining the cerebral and somatic oxygenation levels are valuable to help in clinical management during cardiopulmonary bypass (CPB) and cardiac surgery as a whole.

The aim of this study was to evaluate the effect of total intravenous anesthesia (TIVA) and inhalational anesthesia techniques on tissue oxygenation in cardiac surgery. For this purpose, the effects of midazolam-based TIVA or sevoflurane-based inhalation anesthesia maintenance on intraoperative central and somatic tissue oxygenation parameters were compared in patients undergoing cardiac surgery.