In cardiac operations, high values of blood lactate have been associated with bad outcomes if detected both during CPB and at the arrival in the intensive care unit (ICU) in adult patients. Many studies highlighted the potential role of hyperlactatemia on admission to the ICU as a marker for adverse outcome, and one study linked hyperlactatemia during CPB with postoperative morbidity and mortality. Evidence that both CENTRAL VENOUS SATURATION (ScVO2) and blood lactates during CPB are potential early predictors of morbidity and mortality in adult cardiac operations are still lacking.

Inclusion Criteria:

cardiac surgical patients who will undergo isolated elective CABG and fulfill these criteria:

1. Aged 18 years or above.
2. Operated with cardiopulmonary bypass.

Exclusion Criteria:

1. Preoperative lactate level greater than 3 mmol/l.
2. Redo surgery.
3. If the patient will be reoperated during the study time.
4. Preoperative hemoglobin level less than 10 mg/dl.
5. Ejection fraction (EF) of <30%.
6. Renal impairment.
7. Liver impairment.
8. History of stroke and significant carotid artery stenosis.
9. Chronic obstructive or restrictive lung disease.