Whole-blood transfusions reduce mortality in massively hemorrhaging patients
For most of the last 250 years, whole blood was the only option for patients needing transfusions after surgery or major trauma. The transition from whole blood to component therapy — which uses stored blood that has been leukoreduced and separated into plasma, platelets and red blood cells (RBCs) — began in the 1970s. By 1990, component therapy had become standard practice in trauma surgery.
According to Donald Jenkins, M.D., director of the Level I Trauma Center at Mayo Clinic's campus in Rochester, Minnesota, the move away from whole blood wasn't driven by data comparing the risks and benefits of the different types of transfusions but by practicality — modern preservatives allow blood components to be stored up to 42 days; a newly FDA-approved preservative will allow storage out to 56 days.
Yet several large, retrospective studies question whether blood cells actually remain functional that long. A 2008 study published in The New England Journal of Medicine found that post-surgical complications and mortality were increased in patients receiving blood stored more than two weeks — possibly due to high concentrations of hemoglobin, free iron and red blood cell fragments.
Furthermore, component blood, even when given in a 1-1-1 transfusion ratio (equal parts plasma, platelets and packed RBCs) — the standard of care in the resuscitation of severe hemorrhage — replicates but does not duplicate whole blood. In the May 2014 issue of Surgery, Mayo Clinic researchers note that component blood contains "a myriad of additives," including dextrose, mannitol, sodium phosphate, sodium bicarbonate, sodium chloride, citric acid, phosphate, dextrose and adenine. This fluid is also anemic, thrombocytopenic and acidotic, with 40 percent less concentration of coagulation proteins.
The better alternative to this chemical solution, the authors argue, is real whole blood — either stored or fresh.
Stored whole blood vs. WFWB
Stored whole blood has three main advantages:
- Fewer impurities compared with component blood
- Exposure of recipients to blood from a single donor
- Preservation of platelet function for longer periods of time
During the Vietnam War, for example, more than 1 million units of stored whole blood were transfused with platelet function well-maintained.
Whole blood does have the potential for incompatibility in patients with unknown blood types, but using universal donor group O blood can reduce some of the risk. Furthermore, stored whole blood undergoes the same testing as components and is fully approved by the FDA and the American Association of Blood Banks (AABB).
Still, Dr. Jenkins maintains that despite the advantages of stored whole blood, warm fresh whole blood (WFWB), which is transfused within minutes to 24 hours of collection, remains the gold standard for resuscitation of hemorrhagic shock because it most closely resembles the blood patients are losing.
Data support this point of view. From 2003 to 2007 in Iraq and Afghanistan, more than 500 soldiers with life-threatening injuries were transfused with WFWB. Those patients showed improved 48-hour and 30-day survival compared with massively hemorrhaging patients who received stored red blood cells. The success of WFWB for hemorrhage control in the military has sparked interest in using it for civilians who are severely injured in mass disasters.
But implementing WFWB in civilian and even military settings presents enormous challenges. Fresh blood is more likely to transmit infections, including hepatitis C and HIV, than is stored whole blood or component therapy because it can't be tested prior to transfusion. And it is not approved for civilian use by either the FDA or AABB. The only military indications are a short supply of whole blood components or the failure of 1-1-1 transfusion ratio resuscitation.
Dr. Jenkins and colleagues at Mayo Clinic say there is overwhelming evidence supporting the use of group O stored whole blood for massively hemorrhaging patients and have established a stored whole-blood transfusion program at the Rochester campus, with the intention of storing two to five units of whole blood up to 21 days. Royal Caribbean Cruise Lines recently implemented a similar program and has successfully transfused over 30 patients. The University of Pittsburgh intends to start a stored whole-blood program in early October.
For Mayo Clinic, the ultimate goal is to expand the program to include WFWB if research can prove its safety and efficacy. "Fresh whole blood remains the Holy Grail for the resuscitation of hemorrhagic shock," Dr. Jenkins says.
For more information
Koch CG, et al. Duration of red-cell storage and complications after cardiac surgery. The New England Journal of Medicine. 2008;358:1229.
Zielinski MD, et al. Back to the future: The renaissance of whole-blood transfusions for massively hemorrhaging patients. Surgery. 2014;155:883.