Blood Donors and the Supply of Blood and Blood Products (1996) / Chapter Skim
Currently Skimming:
I Current State of the Blood Supply
I Current State of the Blood Supply
Pages 1-30
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Current State of the Blood Supply
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Blood is collected by two types of institutions in the United States: regional blood centers and hospitals. In 1992, estimated domestic blood collections included 12,035,000 units of allogeneic blood, i.e., blood donated by others; 1,1 17,000 units of autologous blood, i.e., blood donated by patients for their own expected use; and 436,000 units of directed blood, i.e., blood donated by others for use by designated patients (Table 1)
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As for directed units, only 31 percent were transfused. The findings from this survey indicate that over 1.5 million units of allogeneic red cells from the national blood resource were outdated, lost, or unaccounted for during 1992 (Table 1~.
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Douglas Surgenor: It is an interesting problem. In a cohort of over 500 total hip replacement patients who had predeposited autologous units, we observed that the proportion of patients who completely avoided transfusion with allogeneic units increased as the number of units predeposited increased from one up to four units.
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Douglas Surgenor: That is a fact, but we don't know the factors that may be driving autologous and directed donations. Ernest Simon: I think the point you made is that there were a million units that are unaccounted for.
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CURRENT STATE OF THE BLOOD SUPPLY 7 blood resource is spread over these several thousand hospitals in the United States. In addition to actual outdating, there is loss due to breakage, handling, and Mat sort of thing.
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Today I am focusing on short-term fluctuations, where it is necessary to tailor the blood availability to specific patient needs. Over the longer term, there will be shifts in blood utilization based on changes in medical therapy and changes in the indications for transfusion, leading to variations in the blood supply.
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Medical meetings other than surgical meetings usually don't have that much of an effect on blood utilization. Another source of variation can be one or two particular patients, such as a major trauma case, who might use 50, 60, or 70 units of red cells.
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If these collection goals were tightly related to the projected blood needs, these time periods would be potential problems of lack of supply. The American Red Cross national data for June 1992 to April 1995 (Figure 2, kindly provided by Brian McDonough)
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Another consideration is work or manufacturing plant schedules, depending on how the manufacturing plant is running and whether or not they change their schedules. Probably the most important factor, however, that determines blood availability and consistency of supply is the donor recruitment staff at the blood center.
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Jeffrey McCullough: There is a related theme that I would like to mention. A friend and colleague of mine in Minneapolis, Herb Polesky, got into a fairly vigorous debate at the state medical association meeting a few years ago when he took the position that it was okay periodically to have blood shortages because it brought to the attention of the physicians that blood is not just a casual resource out there in unlimited supply.
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The first is the data that you presented were for red cells. Is there a problem with platelets as well, which clearly are different with the increase in growth of single donor platelets?
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I suspect that if you look at the same data Mom the standpoint of the so-called blood center you may find they don't fluctuate a great deal because when one hospital is up, another one is down. The exceptions would be smaller blood centers and places where there is one major hospital that uses almost all of the blood supply, so that their fluctuation goes to the blood center.
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I will then show you some relevant animal data, and finally I will turn to two studies that we are in the process of completing,: one we call Anemia and Surgery and the second is Surgical Blood Transfusion Variation and Outcome. I will try to convince you that we need large randomized clinical trials to answer this question definitively and that we will never know what the appropriate use is unless we get more data.
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. Then in 1988, NIlI's consensus conference rejected the 10-30 rule and said that this doesn't make sense, that we ought to not be using specific hemoglobin criteria, and that we ought to be looking at other factors tic well The consensus conference suggested that perhaps 7 to 8 ~'dl is a ~ _ ~ ^~ ^~ -^~ =~ r ~ -r - ~ more appropriate hemoglobin level for deciding to transfuse.
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At a hemoglobin level of 5 g/dl, changes on the ST segment of the electrocardiogram begin, and below 3 Jdl, lactate production and decreased ventricular function begin and the animals begin to die. The second point is that when coronary artery disease is experimentally induced by tying off animals' coronary arteries, reducing blood flow 50 to 70 percent, these animals are much less tolerant of anemia than normal animals.
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We expect that the variation study will evaluate the effect of blood transfusion on this death rate and how at different hemoglobin levels transfusion affects postoperative mortality and morbidity. Both of these studies are observational, however, and we will never know for sure if we completely control for confounding variables.
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However, additional data are required to determine who truly should be transfused, and I think a randomized trial is clearly needed. Without such data, it is very hard for me to answer the question of whether red cells are being appropriately used.
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If you are very anemic, you may make the platelets dysfunction, and therefore, you are going to bleed more. So, it would be important to consider surgical patients who are bleeding to be in need of transfused red cells, regardless of their hemoglobin level, to help platelet fimction.
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However, I didn't spend much time in Geneva looking at Western European blood programs. I spent a lot of time looking at developing programs, so I don't consider myself an expert on blood transfusion in Western Europe.
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First, we have a tremendous number of donors who are deferred for unnecessary reasons. The American Red Cross alone defers 1.2 million donors per year because of elevated liver enzymes (ALT)
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For example, ALT testing, HBV core testing, and HTLV-1 and -2 testing are not done in most of the major European countries. The Europeans have also made the absolutely marvelous discovery that the best place to store blood is in the human body.
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First of all, in general, the collection andlor public education responsibility in Western European countries is given to a single authority in the country, generally under the auspices of some kind of national blood program and policy. Another major difference is that the people responsible for collectio and/or donor recruitment invest a major effort at the very highest levels to meet with their counterparts in other organizations and get the recruitment message out to the public.
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They receive an invitation to visit the doctor, their own or the blood center's. In the United States, they are judged, sentenced, and practically put away by mail with some of these awful letters that all of you know about.
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. Who should be our blood donors?
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