Background: The rationale of RBC transfusion is to improve oxygen transport and ultimately tissue oxygenation.1 STS/SCA Clinical Practice Guidelines suggests the transfusion of red cells in most postoperative cardiac patients with hemoglobin level of 7g/dL or less. Mixed venous oxygen saturation reflects the balance between the oxygen delivery and demand. This study determined the correlation of the mixed venous oxygen and current practice of blood transfusion in terms of the physiologic and clinical outcomes of post-CABG patients.
Method: One hundred eight patients undergoing CABG were enrolled. Participants were assigned into four groups according to their baseline SvO2 and with the compliance to the recommendation on blood transfusion. The patients were grouped accordingly as follows: Group 1- Compliant- (Hgb >a7g/dl -No blood transfusion) +SvO2 ≥ 65%, Group 2- Compliant (Hgb >7g/dl- No blood transfusion) +SvO2 < 65%,Group 3- Non-compliant ( Hgb >7g/dl-With blood transfusion) +SvO2 ≥ 65%, Group 4- Non-compliant ( Hgb >7g/dl- with blood transfusion) +SvO2 < 65%.Changes on the physiologic parameters and the clinical outcomes were observed during the 1st hour on admission and on the 12th at SICU.
Results: Only patients with hemoglobin of >7g/dl were included in the study. Thirty-two of the 108 patients were given transfusion despite the lack of indication as per hemoglobin trigger. The study shows that there are no statistically significant differences with the outcomes of the patients after 12 hours at SICU among the four groups. Even with the SvO2 of <65% or >65%, giving of blood did not significantly changed the physiologic parameters and the clinical outcome of the patients.
Conclusion: Among the patients with hemoglobin value of >7g/dl, the physical and clinical outcome did not differ. Svo2 may be a useful tool in conjuncture with hemoglobin level that would aid in the decision making to transfuse blood among patients with hemoglobin level of >7g/dl, wherein there is still no clear cut indication for the transfusion of blood among these group of patients