Revisão Revisado por pares

It's time to end RBC shortages

2003; Wiley; Volume: 43; Issue: 12 Linguagem: Inglês

10.1111/j.0041-1132.2003.00634.x

ISSN

1537-2995

Autores

Ronald O. Gilcher,

Tópico(s)

Blood groups and transfusion

Resumo

The “time has come” for new strategies to help alleviate and potentially end the chronic shortage of RBCs, especially group O and D– RBCs. The need for RBCs will continue to drive blood collections in the US. Increasing the active donor base has been the obvious and seemingly simple solution to end RBC shortages. Nevertheless, nothing is simple or easy and this approach alone has failed because we may be subtracting donors faster than we can add them. New strategies are needed. The use of automated RBC collection technology has the potential to increase the total number as well as the specific blood types of RBCs collected, without significantly increasing the number of donors or their frequency of donation.1 In this issue of TRANSFUSION, Snyder and colleagues2 describe their experience with a recently introduced automated collection system (Baxter-ALYX) by collecting 2 RBC units from a single donor. Their work describes the advantages and safety of collections of double (2) units of leukoreduced RBCs (DRBC) as well as the quality of the RBC units collected by this technology.2 Other investigators have also shown the safety and quality of this collection system with respect to donors as well as the RBC products.3-6 This automated collection device is not the first, but is the third such device to be marketed in the US to collect RBC units through automated (apheresis) technology. The first device to collect double RBC units was the Haemonetics 8150, marketed approximately 7 years ago.7, 8 The second device to allow automated RBC collection and double automated RBC collection is the Gambro Trima, initially marketed as a PLT collection device, but that also has multiple-component collection capability. All three of these devices are multiple-blood-component collection devices and can specifically collect DRBC units from appropriate donors. The transfusion medicine dictum of “Do not hurt the donor” and “Do not hurt the recipient” remains a constant goal. As part of a newer and more strategic approach to increase RBC collections and specifically increase the collection of the needed blood type of RBCs, automated DRBC collection from a suitable donor can be done without in anyway endangering the donor. It is no longer appropriate to just collect whole blood units through mobile operations that cannot provide the right number or the right type of units because of the random distribution of blood types in the donating population. What most blood centers have done is to use telerecruitment of the more needed types—almost always blood group O—to fill the void. What clearly happens at most blood centers is that the inventory of blood group A units generally is too high and the inventory of blood group O units is almost always too low. The usage of blood group O (especially O–) exceeds the percentage of blood group O in the general and donor population. At the Oklahoma Blood Institute, the usage of blood group O is in excess of 52 percent of the RBCs distributed and transfused whereas our donor population is only 44 to 46 percent group O. In reality, the shortage of RBCs in the US is mainly a group O shortage, although group B supplies can be a problem in areas where African American recipients are a large portion of the population. So, why don’t we get smart and disproportionately collect even more group O than we are currently collecting.9 This disproportionate collection of blood group O by utilizing double RBC collection not only has the advantage of increasing the group O RBCs but also has the advantage of decreasing the group O plasma, which clearly has a limited transfusion requirement. At the Oklahoma Blood Institute, extensive RBC automated collection is used but not just for double RBCs. The need for a more universal transfusable plasma is also present. By utilizing this same technology in the RBC plasma (RBCP) format, blood group A+ donors can provide not only a single group A RBC but a double-volume (450–500 mL) plasma unit. The “double-plasma” unit being blood group A has the transfusion potential to be transfused into 85 to 90 percent of the patient population requiring plasma transfusions. This procedure (RBCP) has the advantage of limiting the relative glut of group A RBCs, while increasing the volume of more useful blood group A plasma. All three of the currently marketed devices (Baxter-ALYX, Gambro-Trima, and Haemonetics 8150) either currently have multiple-component collection capability or will have in the near future. The reality is that virtually no group AB RBCs or blood group O plasma is needed as long as there are enough RBCs and plasma of the “right type” in the system. From a realistic inventory standpoint an excess of group O RBCs, Rh– RBC(s), and group AB plasma (or group A plasma) is valuable and feasible using automated RBC collection technology as the DRBC, the RBCP, or plasma only collection. If this sounds so easy, then why don’t we do it? Because nothing is simple and nothing is easy. There are difficulties in educating donors as well as the blood collection staff who must learn to run an automated collection device and convert former whole-blood donors to automated RBC collection technology. There are problems to overcome in moving equipment to mobile sites, although the Baxter ALYX and Haemonetics 8150 are quite mobile. There are problematic negotiations with management of any blood drive sponsor today to give the extra time necessary for automated collections because the “needle in–needle out” time is longer by 15 to 25 minutes depending on the procedure (DRBC, RBCP, or plasma only). There are issues to be faced in donor selection in that currently the DRBC procedure is limited almost exclusively to men because of height, weight, and Hct restrictions. Cost is also an issue because the disposables are significantly more expensive, especially if the procedure is incomplete.10 Nevertheless, all of these difficulties can be overcome. The ability to infuse saline back to the donor reduces the risk of hypovolemic or relative hypovolemic reactions.11 Relative hypovolemia occurs when the donor does not vasoconstrict or, in fact, vasodilates in the immediate period after donation. This reaction may occur when moved from a cool environment to a warm postdonation area resulting in vasodilatation or in some donors on antihypertensive medication who fail to vasoconstrict. If one looks at the advantages of automated RBC collection and especially double RBC collection, there is much to be gained in reducing RBC shortages. Another advantage of automated RBC collection is a more standardized RBC unit. At least two of the technologies are fixed RBC mass collection devices, meaning that they will collect a fixed predetermined RBC mass regardless of the donor's Hct. The RBC mass of whole-blood-derived RBCs is significantly more variable. In terms of cost-effectiveness, we (at the Oklahoma Blood Institute) have found that a DRBC and a RBCP procedure are more cost-effective than whole-blood-derived RBCs as long as the automated RBCs do not outdate or the procedure for collection is not an incomplete procedure. Testing costs are reduced when allocated to an automated collection procedure that yields at least two full-dose transfusable products (i.e., DRBC or 1 RBC unit + 1 double plasma unit). The overcollection of group A and AB+ RBCs from whole blood procedures is costly when they outdate. There is a theoretical advantage to the patient if both aliquots of the double RBC collection are transfused to the same patient. Interestingly, we have had some hospitals refuse both RBC aliquots from the same donor because their computer systems could not track both a blood unit identification number and a product code and their computer would not “accept” two RBC units with the same blood unit identification number. This problem can be fixed if an increased supply of double RBC collections justifies the information technology investment. The time has come to end RBC and especially group O RBC shortages.12-14 The technology for DRBC(s) is available to disproportionately collect group O RBC(s), which can significantly increase the total number of the “right type” and “right number” of RBCs needed in the US and for the most part utilizing the existing donor bases. Donor acceptance of automated RBC collection technology is very high. Its time has come and it's time to end RBC shortages in the US. Patients and the hospitals that serve them demand a more reliable blood supply than we are currently achieving.

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