This study is a clinical trial that seeks to compare post operation Prednisolone prescription effect on post Coronary Artery Bypass Graft surgery (CABG) inflammatory phase, especially on organ damage reduction, ICU stay, inflammatory mediators level and lung oxidation index between intervention and control group. Patients will be included in the study if they aged more than 18 years and underwent CABG after obtaining a verbal and written consent. Patients with any one of the following conditions will be excluded: • Recent systemic corticosteroid intake. • Bacterial or fungal infection history within the last two weeks. • Any history of adverse reaction to steroids. • Uncontrolled diabetes mellitus. • Renal failure history. • Hepatic failure or liver enzymes elevation. The study sample size is consist of two groups, 50 patients are in each group which are selected by randomization. Intervention group will be prescribed 1mg/Kg bolus dose of prednisolone plus 2mg/Kg/d steady infusion for 24 hours. But the control group will be prescribed 15 mg/kg prednisolon as a bolous sngle dose and normal saline infusion afterthat similar valume to intervvention group as placebo. Before operation C-reactive protein (CRP) and IL-6 and serum cratinin (Cr) will be checked. Post operation assessment will be classified as below: • IL-6 and CRP 6 and 24 hours after surgery • Serum Cr 24 and 48 hours after operation • Post operation Pio2/Fio2, arrhythmia, bleeding, hemodynamic indexes such as blood pressure and central vein pressure, blood sugar, WBC changes in patients, ICU stay duration, renal failure, infection, wound and gastrointestinal complications