Remembering the Classics: Support For The Use Of Fresh Whole Blood in Young Children Undergoing Complex Open Heart Surgery
Lindsey Loveland Baptist, James DiNardo, Viviane Nasr, Susan Nicolson
Today’s remembering the classics PAAD is one I fondly remember and exposed the economics of blood banking to an impressionable young anesthesiologist (me). When you go to the supermarket to buy say milk. Do you look at the label and reach for the freshest milk (usually in the back of the refrigerator case) or simply take the one in the front which is usually the oldest? Obviously the supermarket folks have it figured out and want you to take the oldest milk first. Same for the blood bank. Further, when you buy chicken, do you buy a whole chicken or one that has either been cut into parts or just the parts themselves? The whole chicken is significantly cheaper and the supermarket makes much more from the parts. Hmmmm. sounds like the blood bank doesn’t it? Myron Yaster MD
Original article
C S Manno, K W Hedberg, H C Kim, G R Bunin, S Nicolson, D Jobes, E Schwartz, W I Norwood. Comparison of the Hemostatic Effects of Fresh Whole Blood, Stored Whole Blood and Components after Open Heart Surgery in Children. March 1991; Blood, 77(5): 930-936. PMID: 1995100
In prior PAADs we have written about blood, transfusion, management, and conservation as a cardiac anesthesia group, and now we are revisiting a classic. While fresh whole blood is not consistently available, and some of us remember using it fondly, it’s helpful to look back to the inception of the concept and where some of the data regarding its benefits comes from.
Prior to Bill Norwood coming to CHOP in 1984 to be the division chief of cardiothoracic surgery, he performed surgery in both Boston and with Project Hope in Krakow Poland. In Poland on the morning of surgery, the police and military donated fresh whole blood for that day’s patients. Norwood observed that the Polish children receiving fresh whole blood bled less than patients he operated on in Boston who were transfused with component therapy. Norwood requested fresh whole blood for his patients at CHOP. Through great effort and rule bending, fresh whole blood was initially available. Supportive data became necessary to convince the blood banking community that whole blood resulted in better hemostasis compared to component therapy for them to continue to provide whole blood.
Between 1987 - 1989 Manno and colleagues (including Susan Nicolson, one of our PAAD cardiac reviewers) undertook a study to assess whether the use of fresh whole blood is associated with improved hemostasis following cardiopulmonary bypass in infants and children. They performed a double blind trial comparing 24h blood loss in 161 patients whose pump prime (to achieve a hct of 25%) and immediate post-operative transfusion requirements were met with one of 3 blood products.
Assignment to treatment groups was not random but dependent, in part, on the ability of families to provide directed donors for whole blood.
Group 1 – received very fresh whole blood (VFWB) defined as <6hrs old, never refrigerated
Group 2 – received fresh whole blood (FWB) that had been collected 24-48h prior to transfusion and stored at 4-6 degrees C
Group 3 – received reconstituted whole blood (Recon WB) composed of one unit each of PRBCs, FFP, and platelets. These components, usually transfused individually, were combined for study purposes.
Due to limited availability of VFWB and the need to enroll equal number of patients into each treatment group, the following schedule was devised. For patients whose parents were able to provide directed donors, 2/3 were assigned to group I and 1/3 assigned to group 2. For patients whose parents were unable to provide directed donors, 1/3 were assigned to group 2 and 2/3 were assigned to group 3. For infants undergoing emergency procedures assignment was made on an equal basis to the 3 treatment groups using blood from non-directed donors.
The 3 patient groups were comparable with respect to patient age, pre-op coagulation profiles (bleeding time, PT, activated PTT, platelet count and aggregation, fibrin split products, fibrinogen), surgical difficulty as graded by the surgeon, and mean bypass and circulatory arrest times.
The authors found that overall 24h mean blood loss in mL/kg was 50.9 +/- 9.3 in VFWB Group 1 , 44.8 +/- 6.0 in FWB Group 2, and 74.2 +/- 8.9 in Recon WB Group 3 (p = .03). Differences in blood loss among groups varied according both to the age of the child and to the complexity of the surgical procedure. Comparison of the 93 children less than 2y of age showed the transfusion of Recon WB was associated with 85% more blood loss than either of the other products (p=0.001). Mean blood loss in the 68 children > 2y did not show significant difference among treatment group. For patient undergoing surgery of simple or intermediate complexity no differences in blood loss occurred. For patient undergoing complex procedures, blood loss differed significantly with patients receiving Recon WB having the highest blood loss. This difference was more profound in children less than 2y old having complex surgery who losses were replaced with Recon WB.
All groups showed changes in coagulation profiles post bypass. Mean activated clotting time at 30 min after protamine was similar in all groups. However, 30 min after protamine Recon WB Group 3 subjects had a longer mean aPTT and a lower mean fibrinogen compared with the other groups. Recon WB was associated with the most abnormal platelet aggregation studies at 30 minutes and ADP aggregation at 3h was also significantly reduced.
Take away: Use of WB <48h old for pump prime and post bypass transfusion in children <2 years of age undergoing complex open heart surgery had significantly less post operative hemorrhage in comparison with transfusion with stored blood components. The authors postulate that the benefit of fresh WB may be the presence of better functioning platelets. Additionally, the authors found that VFWB and 24-48 hour old WB had similar hemostatic effect. Use of 24-48 hour old WB allows blood to be screened for infection, stored, and irradiated to eliminate the risk of graft versus host disease. The study also suggests that finding ways to improve platelet function in stored platelets may be another important way to decrease blood loss.
Whole blood is the simplest and most common type of donation. However, the blood banking community routinely fractionates whole blood into components for economic reasons as most transfusion needs are met with component therapy. The COVID pandemic has resulted in fewer donors and less personnel at donor centers which further reduces the availability of fresh whole blood for a patient population where its efficacy has been shown. Currently a study sponsored by the Department of Defense is ongoing to compare post bypass blood loss in children and adults who receive room temperature stored platelets with those whose platelets have been stored cold.
Is your blood bank able to provide fresh whole blood? Consistently? What patient populations do you use it for?