Mortality associated with standard prescription transfusions in cardiac surgery

Before applying new blood management strategies, the extent of blood product transfusions and its correlation with perioperative mortality should be identified.

This study retrospectively analyzed the extent of perioperative transfusions of red blood cells (RBC), fresh frozen plasma (FFP), and platelets (PLT) in 565 consecutive cardiac surgery patients, who received transfusions based on standard prescriptions. Patients were stratified in four groups according to perioperative transfusion units (no transfusion, <5, 5-10, >10 units). Mortality was analyzed in relation to the type and extent of each blood product transfused and their combinations. Subsequently, the ability of transfusion volume to predict mortality was tested.

Most patients received blood product transfusions perioperatively.  The observed mortality (11.7 %) correlated significantly with the volume of transfusion. Patients transfused with >5 RBC or FFP units or >10 PLT units had increased mortality compared with those receiving fewer transfusions (23.9 % vs 4.5 %, 27.4 % vs 6 %, 24.5 % vs 8.5 %, p <0.05, respectively). Analysis revealed that cutoffs of >5 units of RBC or >15 units of RBC, FFP, and PLT additively (sensitivity: 74.2 % and 72.7 %, specificity: 68.7 % and 69.5 %, respectively) had an acceptable discrimination ability for perioperative mortality (Area under the ROC curve: 0.756, p <0.001, and 0.735, p <0.001, respectively).

This study confirmed a dose-dependent, transfusion-associated, increased mortality in cardiac surgery patients who received standard prescription transfusions. The results support the need for applying validated, patient-specific blood conservation strategies that correspond to the patient's actual perioperative transfusion needs. HIPPOKRATIA 2018, 22(2): 68-74.