Impact of Preoperative Oral Carbohydrate Loading on Insulin Resistance in Adult Cardiac Surgery Patients

The goal of this clinical trial is to investigate the effect of preoperative oral carbohydrate on insulin resistance in adult cardiac surgery patients with a cardiopulmonary bypass machine. Insulin resistance is when the body does not respond well to insulin, which can raise blood sugar and slow recovery. The main question this study aims to answer is: Does drinking a carbohydrate drink 2 hours before surgery lower insulin resistance compared to drinking only water after on pump cardiac surgery? Researchers will compare two groups: One group will drink 400 milliliters of a maltodextrin (carbohydrate) drink (CL group). The other group will drink 400 milliliters of water (PL group). Participants will: 1. Be randomly assigned to one of the two groups. 2. Have blood samples taken to measure insulin and glucose before and after surgery (at hour-0, and hour-24 after ICU admission). 3. Be monitored in the intensive care unit for 24 hours after surgery.