A new practical technique to reduce allogeneic blood exposure and hospital costs while preserving clotting factors after cardiopulmonary bypass: the Hemobag®

Recent data independently linking allogeneic blood use to increased morbidity and mortality after cardiopulmonary bypass (CPB) warrants the study of new methods to employ unique and familiar technology to reduce allogeneic blood exposure. The Hemobag® allows the open-heart team to concentrate residual CPB circuit contents and return a high volume of autologous clotting factors and blood cells to the patient.

Fifty patients from all candidates were arbitrarily selected to receive the Hemobag® (HB) therapy. A retrospective control group of 50 non-Hemobag® (NHB) patients were matched to the HB group patient-by-patient for comparison according to surgeon, type of procedure, age, body surface area (BSA), body weight and CPB time. Many efforts to conserve blood (Cell Saver® and ANH) were employed in both groups. Post-CPB cell washing of circuit contents was additionally employed in the control group.

There were no significant differences between the HB and NHB groups in regard to patient morphology, pre-op cell concentrations, distribution of surgeon or procedures (41% valve, 16% valve/coronary artery bypass graft (CABG), balance CABG), pump and ischemic times and Bayes National Risk scores. The average volume returned to the patient from the HB was 8179/198 mL (1 SD). Average processing time was 11 min. The Hemobag®contained an average platelet count of 2309/80 K/mm3, fibrinogen concentration of 4139/171 mg/dl, total protein of 8.09/2.8 gm/dl, albumin of 4.49/1.2 gm/dl and hematocrit of 439/7%. Factor VII, IX and X levels in three HB contents averaged 259% greater than baseline. Substantial reductions were achieved in both allogeneic blood product avoidance and cost to the hospital with use of the HB.

Infusion of the Hemobag® concentrate appears to recover safely substantial proteins, clotting factor and cell concentration for all types of cardiac procedures, maintaining the security of a primed circuit.

Improved coagulation and blood conservation in the golden hours after cardiopulmonary bypass

The Hemobag (HB) technique allows the open-heart team to safely concentrate the residual cardiopulmonary bypass (CPB) circuit contents and return a high volume of concentrated clotting factors and blood cells back to the patient as autotransfusion. Hematocrit, platelet count, fibrinogen concentration ([Fib]), prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR) were compared between two prospective convenience groups of cardiac surgical patients whose residual circuit blood was processed by the HB (n=10) or by the Cell Saver (CS; n=10) at two times after CPB: (a) after acute normovolemic hemodilution (ANH) infusion and protamine administration and (b) after admission to the intensive care unit (ICU), approximately 1 hour after CPB and HB content infusion. Minimal cell processing was also used in the HB patients to conserve blood. "Golden hours" is defined as the first few hours after CPB and protamine sulfate administration and extend into the ICU, when maintaining hemostasis is vital during cardiac surgery and is the most susceptible period for blood product administration and the opportunity to improve patient outcome. Except for PTT, all parameters changed significantly from the ANH infusion and protamine administration to approximately 1 hour after HB blood infusion and arrival in the ICU. Fibrinogen (p = .048) and hematocrit (p = .046) were significantly higher in the HB group compared with the CS group at the end of the golden hour despite infusion of significantly more allogeneic blood products (p = .070) and more washed red blood cells (RBCs; p = .001) in the CS group. All but one of the HB patients did not receive any allogeneic blood products during the golden hours. Use of the HB technique for salvaging blood is associated with significant increases in the patient's protein and cellular concentrations and lowered coagulation times in the important, first few golden hours after CPB, and except for one patient, without the addition of expensive and precarious allogeneic blood products.