This study aims to evaluate the effect of low tidal volume (LTV) ventilation during cardiopulmonary bypass (CPB) on postoperative delirium. It is hypothesized that the risk of delirium, which negatively impacts recovery following cardiac surgeries, can be reduced by improving cerebral perfusion and oxygenation through LTV. The study is designed as a prospective, randomized, controlled trial comparing delirium incidence, ICU stay duration, and 30-day mortality/morbidity rates between LTV and apnea groups. Primary outcomes will be assessed using the 3D-CAM method, while secondary outcomes include ICU stay duration and mortality/morbidity rates.