Evaluation of the quotient of the venoarterial carbon dioxide gradient and the arteriovenous oxygen content difference as a transfusion trigger parameter in hemodynamically stable patients with significant anemia

Forty-five postoperative patients admitted to our cardiac ICU were enrolled between
January 2013 and September 2014. Three groups were defined according to the trend
of blood loss over the surgical drains in the first 24 postoperative hours. Mild blood
loss was defined as 500 to 1,000 ml/24 hours, moderate (1,000 to 1,500/24 hours) and
severe (1,500 ml/24 hours). In addition to the ?PCO₂ the following parameters were monitored: CI, CO, SVR, serum lactate, ScvO₂ and hemoglobin. Ca-cvO₂ was calculated and the ?PCO₂/ Ca-cvO₂ quotient was assessed for a total of 400 paired blood samples. All enrolled patients
were hemodynamically stable. A retrospective analysis of this data was performed.