Improved Coagulation After Cardiopulmonary Bypass Using the Hemobag ® Scott R. Beckmann, B.S.,C.C.P. Thomas Winkler, M.D., William Shely, M.D., Salem Hospital, Salem, OR, USA There are increasing international stresses within healthcare regarding the allogeneic blood supply, its use and associated costs and morbidity (1). The concern is arguably one of greatest in the cardiac surgery arena today (2). Improved blood administration practices have been encouraged by multiple professional societies whose members provide cardiac surgical care. (3-4). There are vast differences in transfusion practices between cardiac surgical facilities throughout the world (5). As well, there are numerous blood conservation maneuvers that are employed during cardiac surgery that have not been widely adopted as standard of care (6-8). Patient data from an underutilized ultrafiltration technique (the Hemobag ® ) to process residual extracorporeal circuit blood is presented as an example of a means to reduce allogeneic blood related risks and costs (9). This technology allows for the infusion of shed / residual blood without creating disturbances in hemodynamic or biochemical parameters, and avoidance of clinical complications or any increase in morbity (9-10, 16-17). Further studies indicate that in over 50% of patients, FFP transfusion does not reliably reduce the PT or INR and exposes patients to unnecessary risk (18-19). A prospective, evenly matched two-cohort case series design was constructed. Hematocrit, platelet count, fibrinogen concentration ([Fib]), PT, PTT and INR values were compared in 10 Hemobag ® (HB) and 10 non-HB (NHB) adult cardiac surgical patients at two times after CPB: 1) post acute normovolemic hemodilution (ANH) infusion and protamine administration, and 2) after admission to the ICU approximately one hour after CPB and HB infusion. An ANH volume (about 4 cc/kg) was withdrawn from each patient after heparinization, sequestered and returned immediately after protamine administration in both the HB and non-HB patients. Cell processing (Cell Saver ® 5; Haemonetics Corporation, Braintree MA) was also employed in both groups of patients to conserve blood. Immediately post-bypass, the residual CPB circuit blood was processed by the Cell Saver ® 5 in the NHB patients and the Hemobag ® technique was utilized in the HB patients (Figure 1). Residual heparin in the HB contents was neutralized with an additional 50mg of protamine sulfate after infusion. The decision to transfuse allogeneic blood bank products was made by the same physicians using the same transfusion criteria for both groups of patients during the time periods in this study. Process indicators and central hospital laboratory results were statistically compared by independent group t-test or ANOVA between the NHB and HB patients before and after the first hours immediately after protamine administration and the reinfusion of ATS, ANH and HB blood. Specific factor comparisons were made employing Bonferroni adjustments. The alpha level was set at 0.05 or 0.10 depending on the factors. Statistical analysis was performed using SPSS software (SPSS 14.0, Chicago, IL). Table 1 lists the patient-by-patient allogeneic, ANH, ATS and Hemobag ® volumes used in the few hours immediately post- protamine sulfate infusion. Figure 2 shows the difference between CPB and HB blood parameters. Table 2 presents the results of the statistical analysis of the differences between groups. Except for PTT, all parameters changed significantly from the post-protamine and HB, ATS and ANH blood infusion to approximately one hour after and arrival in the ICU. Figure 3 reports the cost savings by employing the Hemobag®. Fibrinogen and Hct (Figure 4) were significantly higher in the HB group at the end of the first ICU hour. Significant reductions in PT and INR were also observed after HB content infusion however, there was only a strong trend in decreased average PTT. NHB patients required significantly more donor blood products than the HB patients where nine of the ten patients required no allogeneic blood during their hospital stay. The Hemobag ® Blood Salvage Device is a reservoir system that allows the patient’s own whole blood to be salvaged, quickly hemoconcentrated and safely infused. It efficiently uses the same convenient reservoir bag while insuring CPB circuit integrity for reinstituting bypass safely and securely, if necessary. Table 1 Method Results Discussion Introduction Group PatientPlt PkgRBCFFPCryoANHHB VolATSDnr Exp Non- Hemobag ® Patients Hemobag ® Patients Note: The number of platelet packs (Plt Pkg), units of red blood cells (RBC), fresh frozen plasma (FFP) and cryoprecipitate (Cryo) transfused in the first hours after protamine infusion. ANH is acute normovolemic hemodilution and ATS is autotransfusion washed RBCs. Donor exposures (Dnr Exp) are the total number of allogeneic donor exposures observed. Table 2 ParameterTreat Post CPB In ICU ICU p HB p Event p Interact p HctNon-HB24.7 +/ / < HB24.3 +/ /- 2.3 Dnr ExpNon-HB*2.7 +/- 7.4*0.107** HB*0.8 +/- 2.5 RBCsNon-HB*1.3 +/- 2.0*0.07** HB*0 PltNon-HB*1.7 +/- 3.1*0.169** HB*0.2 +/- 0.6 FFPNon-HB*1.7 +/- 2.5*0.159** HB*0.4 +/- 1.3 CryoNon-HB*1.0 +/- 3.2*NS* HB*0.2 +/- 0.6 ATSNon-HB*1039 +/- 613*0.001** HB*248 +/- 166 INRNon-HB1.6 +/ /- 0.1NS 0.021NS HB1.6 +/ /- 0.1 PTNon-HB19.2 +/ /- 1.4NS 0.002NS HB20.6 +/ /- 1.7 PTTNon-HB35 +/ /- 4NS HB38 +/ /- 7 [Fib]Non-HB195 +/ / NS HB199 +/ /- 63 Plt CntNon-HB90 +/ /- 24NS 0.001NS HB82 +/ /- 40 Note: Values are mean +/- one standard deviation. Hemobag ® effect is between the Hemobag ® (HB) and non-HB groups. ICU is between HB and NHB in the ICU. Event is between post CPB and post one hour. Hemobag ® and allogeneic blood use Figure 4 Fibrinogen Pre and & Post Hemobag ® Infusion Hct% Pre and & Post HB Infusion INR Changes Pre and & Post HB & Blood Product Infusion Savings of Unused Blood Products In the Hemobag ® Group Figure 2 Figure 1 Preserving blood components Figure 3 ** References available on handout copy of poster. QUICK VOLUME LINE FOR ANESTHESIA OR TO THE FIELD (if necessary) 7 NHB pts. received blood products [FFP, Plt, Cryo, RBC] 1 HB pt. received blood products [FFP, Plt, Cryo,] p = NS p = < HB: p = p = < NS HB: p = p = NS All blood products for the Hemobag ® patients’ charges $1,722 vs. $12,563 for the control patients. A difference of: $10,841 Patient charges ϰ 2 (1, N=20) = 6.11, p < patients 1 patient Post-Protamine Post-Infusion Most allogeneic blood products are transfused in the first few perioperative hours and often based upon arbitrary clinical observations without adequate documentation of the need for blood bank components (3). The results of this case series strongly suggest that cardiac surgery patients may be spared donor exposures when the residual bypass circuit blood is highly concentrated and quickly reinfused as compared to cell washing (9-10). Use of the Hemobag ® for salvaging blood is associated with significant increases in the patient’s protein and cellular concentrations, that would have normally been discarded (average of costs of lost proteins +/- 4,000USD) (15) thus lowering coagulation times in the important, first few hours following CPB (11-14). Use of “multi-pass” ultrafiltration (UF) to process the residual perfusion circuit blood far exceeds the results of “single-pass” ultrafiltration methods. This technique has improved our blood administration practices and helped avoid many unnecessary transfusions. The Hemobag ® patients obtained significantly improved coagulation parameters with far fewer blood products than were required in the non-HB patients. The Hemobag ® provides patients with improved quality of care through the reduction of allogeneic blood products. Frequently, transfusions are directly related to costly, negative, patient outcomes and in many cases can be avoided (20). The Hemobag ® now offers perfusionists a new role in optimizing homeostasis & coagulation in the first few critical hours after the termination of cardiopulmonary bypass. Post-Protamine Post-Infusion