Evaluation of blood transfusion effects on mixed venous oxygen saturation and lactate levels in patients with SIRS/sepsis.

PURPOSE To evaluate the effects of red blood cell transfusion in patients with SIRS/sepsis who presented hemoglobin levels under 9.0 g/dL at intensive care unit admission, using two parameters of organ perfusion: mixed venous oxygen saturation and serum lactate levels. METHODS All patients admitted to the intensive care unit with SIRS/sepsis, as defined by Consensus Conference in 1992, and hemoglobin levels under 9.0 g/dL were included. Hemoglobin levels, mixed venous oxygen saturation, and lactate levels were collected before red blood cell transfusion (pre-T) and up to 1 hour after transfusion (post-T). These variables were analyzed through a paired t test, and results were considered significant if P < .05. RESULTS Twenty-nine patients (17 male, 12 female) with ages of 61.9 +/- 15.1 (mean +/- SD) years (range, 21-85 years) and a mean APACHE II score of 12.5 +/- 3.75 (7-21) were transfused with a mean of 1.41 packed red cell units. A significant increase in hemoglobin levels was reached by blood transfusion, from 8.14 +/- 0.64 g/dL (pre-T) to 9.4 +/- 0.33 g/dL (post-T), with P <.001. However, this was not accompanied by a significant change in lactate levels, from 1.87 +/- 1.22 mmol/l (pre-T) to 1.56 +/- 0.28 mmol/l (post-T), with P =.28, or in mixed venous oxygen saturation, from 64.3 +/- 8.52% (pre-T) to 67.4 +/- 6.74% (post-T), with P = .13. The results were similar even in patients with hemoglobin levels under 8.0 g/dL (n = 9). These results suggest that red blood cell transfusions, in spite of leading to a significant increase in hemoglobin levels, are not associated with an improvement in tissue oxygenation in patients with SIRS/sepsis and hemoglobin levels < 9 g/dL.