Influence of tissue perfusion on the outcome of surgical patients who need blood transfusion.

Purpose: The aim this study was to evaluate the clinical outcome of patients needing intra-operative blood transfusion by tissue perfusion markers.
Methods: A prospective single center cohort study. Adult patients needing blood transfusion during the intra-operative period were recruited.
Results: This study included 61 patients. At the time of blood transfusion the hemoglobin level was 8.4+/-1.8 g/dL. Scv02 has been the best tissue perfusion marker to determine mortality, compared with hematemetric values and other tissue perfusion markers, with a cut-off point at ROC curve equal to 80% (AUC=0.75; sensitivity=80%; specificity=65.2%). Patients who received blood transfusion and had Scv02 <or=80% (N=29), in comparison to those with Scv02>80% (N=32), had lower mortality rates (12.5% vs. 47.1%; p=0.008) and lower incidence of postoperative complications (58.9% vs. 72.9%; p=0.06). Blood transfusion with a Scv02 <or=80% was also associated with reduced use of vasopressors (5.9% vs. 36.8%; p=0.009). Lower incidence of hypoperfusion (17.6% vs. 52.6%; p=0.009), and lower incidence of infection (23.5% vs. 52.6%; p=0.038) in the postoperative period.
Conclusions: In major surgeries, Scv02 appears to be an important variable to be taken into consideration to decide for or against blood transfusion, since blood transfusion with adequate perfusion, reflected by Scv02>80%, are associated with worse clinical outcomes.