Blood Transfusion in ICU after Cardiac Surgery: A Lower Hemoglobin Level is Tolerated Liberal Versus Conservative Packed RBCs Transfusion after Open Heart Cardiac Surgery

Background: In patients undergoing cardiac surgery, currently RBC transfusion has been associated with adverse outcome. Evidence regarding optimal blood transfusion practice in those patients is lacking. Objectives: To challenge the hemoglobin transfusion trigger of <9gm/dl compared to a trigger level of 7gm/dl. Design: A prospective randomized controlled Study. Setting: 19 beds post cardiac surgical Intensive care unit in a tertiary care hospital. Patients and Methods: All patients who had open heart cardiac surgery were randomized immediately after admission to ICU into liberal (transfusion trigger is Hb <9.0 gm/dL) or conservative (transfusion trigger is Hb <7.0 gm/dL) strategy. Primary end points were 30 days all cause mortality and lab parameters of tissue perfusion (Lactate and ScVO 2). Secondary end points were clinical complications and length of ICU or hospital stay. Results: There was a non significant decrease in 30 days mortality in the conservative strategy compared to liberal strategy (5.8% vs. 7.4% respectively, p=0.08). No statistical significant difference in the perfusion parameters, clinical complications or length of ICU or hospital stay was noted between the 2 groups. Subgroup analysis of the CABG patients showed similar results. Conclusion: Hemoglobin level of 7.0gm/dL as a transfusion trigger is not associated with any deleterious effect on 30 days mortality or tissue perfusion nor had any increase in clinical complications. Key Wards: Blood transfusion liberal – Conservative open heart – Cardiac surgery.