Liver Function Tests Following Open Cardiac Surgery

Introduction: The cardiopulmonary bypass may have multiple systemic effects on the body organsas liver. This prospective study was planned to explore further the incidence and significance ofthis change.Methods: Two hundred patients with coronary artery bypass grafting (CABG), were randomlyselected for the study. Total and indirect bilirubin, aspartate aminotransferase, alanineaminotransferase, alkaline phosphatase were measured preoperatively and at 24, 48 and 72hours, following coronary artery bypass grafting. Postoperative value of the liver function testswith respect to hypothermia or hypotension were compared by one way analysis of variance forrepeated measure and compared with t test. Patient’s characteristics with bilirubin value (≤1.5 mgor >1.5 mg) were compared with t test.Results: A significant increase of total bilirubin, aspartate aminotransferase, and alkalinephosphatase were noted in the third postoperative day. Significant relation was seen betweenhypotension and alkaline phosphatase, and aspartate aminotransferase change but hypothermiahad not affected alanine aminotransferase, total bilirubin and indirect bilirubin change. Pumptime, alanine aminotransferase in third postoperative day and direct bilirubin in first and secondday of postoperative period had significant relation with pre and post-operative bilirubin change.Conclusion: Transient but not permanent alterations of hepatic enzymes after coronary arterybypass grafting presumably attributed to the decreased hepatic flow, hypoxia, or pump-inducedinflammation.