Packed red blood cells#Compatibility testing

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Red blood cells are used to restore oxygen-carrying capacity in people with anaemia due to trauma or other medical problems

Whenever a red blood cell transfusion is being considered for a patient, it is good practice to consider not only the haemoglobin level, but also the overall clinical context, patient preferences, and whether there are alternative treatments. If a patient is stable and has a haematinic deficiency, they should be treated for the deficiency (iron deficiency, B₁₂ deficiency, or folate deficiency) rather than being given a red blood cell transfusion.

In adults, blood transfusion is typically recommended when hemoglobin levels are below 70 g/L (7 g/dL) in those who have stable vital signs, unless they have anemia due to a haematinic deficiency. Transfusing at a restrictive haemoglobin threshold of between 70 g/L to 80 g/L (7 to 8g/dL) decreased the proportion of people given a red blood cell transfusion by 41% across a broad range of clinical specialties, including those people who are critically ill. There is no evidence that a restrictive transfusion strategy are stronger associated with death or major adverse events (e.g. cardiac events, myocardial infarction, stroke, pneumonia, thromboembolism, infection) compared with a liberal transfusion strategy. There is not enough information in some patient groups to say whether a restrictive or liberal transfusion threshold is better.{{cite journal | vauthors = Carson JL, Stanworth SJ, Dennis JA, Trivella M, Roubinian N, Fergusson DA, Triulzi D, Dorée C, Hébert PC | title = Transfusion thresholds for guiding red blood cell transfusion | journal = The Cochrane Database of Systematic Reviews | volume = 12 | issue = 12 | pages = CD002042 | date = December 2021 | pmid = 34932836 | pmc = 8691808 | doi = 10.1002/14651858.CD002042.pub5 | collaboration = Cochrane Injuries Group }}{{cite journal | vauthors = Carson JL, Stanworth SJ, Alexander JH, Roubinian N, Fergusson DA, Triulzi DJ, Goodman SG, Rao SV, Doree C, Hebert PC | title = Clinical trials evaluating red blood cell transfusion thresholds: An updated systematic review and with additional focus on patients with cardiovascular disease | journal = American Heart Journal | volume = 200 | pages = 96–101 | date = June 2018 | pmid = 29898855 | doi = 10.1016/j.ahj.2018.04.007 }}{{cite journal | vauthors = Docherty AB, O'Donnell R, Brunskill S, Trivella M, Doree C, Holst L, Parker M, Gregersen M, Pinheiro de Almeida J, Walsh TS, Stanworth SJ | title = Effect of restrictive versus liberal transfusion strategies on outcomes in patients with cardiovascular disease in a non-cardiac surgery setting: systematic review and meta-analysis | journal = BMJ | volume = 352 | pages = i1351 | date = March 2016 | pmid = 27026510 | pmc = 4817242 | doi = 10.1136/bmj.i1351 }}

This refers to transfusing a single unit or bag of red blood cells to a person who is not bleeding and haemodynamically stable followed by an assessment to see if further transfusion is required.{{Cite web|url=http://www.isbtweb.org/working-parties/clinical-transfusion/6-single-unit-transfusion/|title=ISBT: 6. Single unit transfusion|website=www.isbtweb.org|access-date=2019-03-05}}{{Cite web|url=https://www.blood.gov.au/single-unit-transfusion|title=Single Unit Transfusion Guide {{!}} National Blood Authority|website=www.blood.gov.au|access-date=2019-03-05}} The benefits of single unit transfusion include reduced exposure to blood products. Each unit transfused increases the associated risks of transfusion such as infection, transfusion associated circulatory overload and other side effects.{{cite journal | vauthors = Koch CG, Li L, Duncan AI, Mihaljevic T, Cosgrove DM, Loop FD, Starr NJ, Blackstone EH | title = Morbidity and mortality risk associated with red blood cell and blood-component transfusion in isolated coronary artery bypass grafting | journal = Critical Care Medicine | volume = 34 | issue = 6 | pages = 1608–1616 | date = June 2006 | pmid = 16607235 | doi = 10.1097/01.CCM.0000217920.48559.D8 | s2cid = 25960888 }}{{cite journal | vauthors = Guinn NR, Maxwell C | title = Encouraging single-unit transfusions: a superior patient blood management strategy? | journal = Transfusion | volume = 57 | issue = 5 | pages = 1107–1108 | date = May 2017 | pmid = 28425603 | doi = 10.1111/trf.14083 | doi-access = free }} Transfusion of a single unit also encourages less wastage of red blood cells.{{cite journal | vauthors = Berger MD, Gerber B, Arn K, Senn O, Schanz U, Stussi G | title = Significant reduction of red blood cell transfusion requirements by changing from a double-unit to a single-unit transfusion policy in patients receiving intensive chemotherapy or stem cell transplantation | journal = Haematologica | volume = 97 | issue = 1 | pages = 116–122 | date = January 2012 | pmid = 21933858 | pmc = 3248939 | doi = 10.3324/haematol.2011.047035 }}

In adults with upper gastrointestinal bleeding transfusing at a higher threshold caused harm (increased risk of death and bleeding).{{cite journal | vauthors = Odutayo A, Desborough MJ, Trivella M, Stanley AJ, Dorée C, Collins GS, Hopewell S, Brunskill SJ, Kahan BC, Logan RF, Barkun AN, Murphy MF, Jairath V | title = Restrictive versus liberal blood transfusion for gastrointestinal bleeding: a systematic review and meta-analysis of randomised controlled trials | journal = The Lancet. Gastroenterology & Hepatology | volume = 2 | issue = 5 | pages = 354–360 | date = May 2017 | pmid = 28397699 | doi = 10.1016/S2468-1253(17)30054-7 | s2cid = 13767083 | url = https://ora.ox.ac.uk/objects/uuid:afc55851-1e65-4427-976b-e96a6317dfbb }}

A review established that in patients undergoing heart surgery a restrictive transfusion strategy of 70 to 80 g/L (7 to 8 g/dL) is safe and decreased red cell use by 24%.{{cite journal | vauthors = Carson JL, Stanworth SJ, Alexander JH, Roubinian N, Fergusson DA, Triulzi DJ, Goodman SG, Rao SV, Doree C, Hebert PC | title = Clinical trials evaluating red blood cell transfusion thresholds: An updated systematic review and with additional focus on patients with cardiovascular disease | journal = American Heart Journal | volume = 200 | pages = 96–101 | date = June 2018 | pmid = 29898855 | doi = 10.1016/j.ahj.2018.04.007 | s2cid = 49193314 }}

There is less evidence available for the optimal transfusion threshold for people with heart disease, including those who are having a heart attack.{{cite journal | vauthors = Carson JL, Stanworth SJ, Dennis JA, Trivella M, Roubinian N, Fergusson DA, Triulzi D, Dorée C, Hébert PC | title = Transfusion thresholds for guiding red blood cell transfusion | journal = The Cochrane Database of Systematic Reviews | volume = 12 | issue = 12 | pages = CD002042 | date = December 2021 | pmid = 34932836 | pmc = 8691808 | doi = 10.1002/14651858.CD002042.pub5 }}{{cite journal | vauthors = Docherty AB, O'Donnell R, Brunskill S, Trivella M, Doree C, Holst L, Parker M, Gregersen M, Pinheiro de Almeida J, Walsh TS, Stanworth SJ | title = Effect of restrictive versus liberal transfusion strategies on outcomes in patients with cardiovascular disease in a non-cardiac surgery setting: systematic review and meta-analysis | journal = BMJ | volume = 352 | pages = i1351 | date = March 2016 | pmid = 27026510 | pmc = 4817242 | doi = 10.1136/bmj.i1351 }} Guidelines recommend a higher threshold for people with heart disease of 80 g/L (8 g/dL) if they are not undergoing cardiac surgery.{{cite journal | vauthors = Carson JL, Guyatt G, Heddle NM, Grossman BJ, Cohn CS, Fung MK, Gernsheimer T, Holcomb JB, Kaplan LJ, Katz LM, Peterson N, Ramsey G, Rao SV, Roback JD, Shander A, Tobian AA | title = Clinical Practice Guidelines From the AABB: Red Blood Cell Transfusion Thresholds and Storage | journal = JAMA | volume = 316 | issue = 19 | pages = 2025–2035 | date = November 2016 | pmid = 27732721 | doi = 10.1001/jama.2016.9185 }}{{Cite web |date=18 November 2015 |title=Blood transfusion Guidance and guidelines |url=https://www.nice.org.uk/guidance/NG24 |access-date=2018-09-07 |website=NICE |language=en-GB}}

There is insufficient evidence to suggest how to manage anemia in people with blood cancers in terms of transfusion thresholds.{{cite journal | vauthors = Radford M, Estcourt LJ, Sirotich E, Pitre T, Britto J, Watson M, Brunskill SJ, Fergusson DA, Dorée C, Arnold DM | title = Restrictive versus liberal red blood cell transfusion strategies for people with haematological malignancies treated with intensive chemotherapy or radiotherapy, or both, with or without haematopoietic stem cell support | journal = The Cochrane Database of Systematic Reviews | volume = 5 | issue = 5 | pages = CD011305 | date = May 2024 | pmid = 38780066 | pmc = 11112982 | doi = 10.1002/14651858.CD011305.pub3 }}

People with thalassaemia who are transfusion dependent require a higher hemoglobin threshold to suppress their own red cell production. To do this their hemoglobin levels should not be allowed to drop below 90 to 105 g/L (9 to 10.5 g/dL).{{Cite web|url=http://ukts.org/standards/Standards-2016final.pdf|title=Standards for the clinical care of children and adults with thalassaemia in the UK|website=ukts.org|access-date=2018-12-20|archive-url=https://web.archive.org/web/20181214130938/http://ukts.org/standards/Standards-2016final.pdf|archive-date=2018-12-14|url-status=dead}}

There is insufficient evidence to recommend a particular hemoglobin threshold in people with myelodysplasia or aplastic anemia,{{cite journal | vauthors = Gu Y, Estcourt LJ, Doree C, Hopewell S, Vyas P | title = Comparison of a restrictive versus liberal red cell transfusion policy for patients with myelodysplasia, aplastic anaemia, and other congenital bone marrow failure disorders | journal = The Cochrane Database of Systematic Reviews | volume = 2015 | issue = 10 | pages = CD011577 | date = October 2015 | pmid = 26436602 | pmc = 4650197 | doi = 10.1002/14651858.cd011577.pub2 }} and guidelines recommend an individualized approach to transfusion.

There is less evidence for specific transfusion thresholds in children compared to adults. There has only been one randomized trial assessing different thresholds in children, and this showed no difference between a restrictive or liberal transfusion strategy.{{cite journal | vauthors = Lacroix J, Hébert PC, Hutchison JS, Hume HA, Tucci M, Ducruet T, Gauvin F, Collet JP, Toledano BJ, Robillard P, Joffe A, Biarent D, Meert K, Peters MJ | title = Transfusion strategies for patients in pediatric intensive care units | journal = The New England Journal of Medicine | volume = 356 | issue = 16 | pages = 1609–1619 | date = April 2007 | pmid = 17442904 | doi = 10.1056/NEJMoa066240 | doi-access = free }} This trial used similar thresholds to the adult studies, and transfusing when the hemoglobin is less than 70 g/L is also recommended in children.{{cite journal | vauthors = New HV, Berryman J, Bolton-Maggs PH, Cantwell C, Chalmers EA, Davies T, Gottstein R, Kelleher A, Kumar S, Morley SL, Stanworth SJ | title = Guidelines on transfusion for fetuses, neonates and older children | journal = British Journal of Haematology | volume = 175 | issue = 5 | pages = 784–828 | date = December 2016 | pmid = 27861734 | doi = 10.1111/bjh.14233 | s2cid = 3360807 | doi-access = free }}

Neonatal red cell transfusion, and when it is appropriate depends on: the gestational age of the baby; how long since the baby had been born; and also on whether the baby is well or ill.

{{main|Blood compatibility testing}}

To avoid transfusion reactions, the donor and recipient blood are tested, typically ordered as a "type and screen" for the recipient. The "type" in this case is the ABO and Rh type, specifically the phenotype, and the "screen" refers to testing for atypical antibodies that might cause transfusion problems. The typing and screening are also performed on donor blood. The blood groups represent antigens on the surface of the red blood cells which might react with antibodies in the recipient.{{citation needed|date=December 2021}}

The ABO blood group system has four basic phenotypes: O, A, B, and AB. In the former Soviet Union these were called I, II, III, and IV, respectively. There are two important antigens in the system: A and B. Red cells without A or B are called type O, and red cells with both are called AB. Except in unusual cases like infants or seriously immunocompromised individuals, all people will have antibodies to any ABO blood type that isn't present on their own red blood cells, and will have an immediate hemolytic reaction to a unit that is not compatible with their ABO type. In addition to the A and B antigens, there are rare variations which can further complicate transfusions, such as the Bombay phenotype.{{citation needed|date=November 2021}}

The Rh blood group system consists of around 50 different antigens, but that of the greatest clinical interest is the "D" antigen, though it has other names and is commonly just called "negative" or "positive". Unlike the ABO antigens, a recipient will not usually react to the first incompatible transfusion because the adaptive immune system does not immediately recognize it. After an incompatible transfusion the recipient may develop an antibody to the antigen and will react to any further incompatible transfusions. This antibody is important because it is the most frequent cause of hemolytic disease of the newborn. Incompatible red blood cells are sometimes given to recipients who will never become pregnant, such as males or postmenopausal women, as long as they do not have an antibody, since the greatest risk of Rh incompatible blood is to current or future pregnancies.{{cite web|url=http://www.health.gov.nl.ca/health/bloodservices/programs/guidelines_for_blood_component_substitution_in_adults_ver2.pdf|title=Guidelines for Blood Component Substitution in Adults|publisher=Provincial Blood Coordinating Program, Newfoundland and Labrador|access-date=3 November 2011|url-status=dead|archive-url=https://web.archive.org/web/20120414215555/http://www.health.gov.nl.ca/health/bloodservices/programs/guidelines_for_blood_component_substitution_in_adults_ver2.pdf|archive-date=14 April 2012}}

For RBCs, type O negative blood is considered a "universal donor" as recipients with types A, B, or AB can almost always receive O negative blood safely. Type AB positive is considered a "universal recipient" because they can receive the other ABO/Rh types safely. These are not truly universal, as other red cell antigens can further complicate transfusions.{{citation needed|date=December 2021}}

There are many other human blood group systems and most of them are only rarely associated with transfusion problems. A screening test is used to identify if the recipient has any antibodies to any of these other blood group systems. If the screening test is positive, a complex set of tests must follow to identify which antibody the recipient has by process of elimination. Finding suitable blood for transfusion when a recipient has multiple antibodies or antibodies to extremely common antigens can be very difficult and time-consuming.{{citation needed|date=December 2021}}

Because this testing can take time, doctors will sometimes order a unit of blood transfused before it can be completed if the recipient is in critical condition. Typically two to four units of O negative blood are used in these situations, since they are unlikely to cause a reaction.{{cite web|url=http://www.transfusionguidelines.org.uk/docs/pdfs/nbtc_bbt_o_neg_red_cells_recs_09_04.pdf|title=The appropriate use of group O RhD negative red cells|publisher=National Health Service|access-date=3 November 2011|url-status=dead|archive-url=https://web.archive.org/web/20120429003714/http://www.transfusionguidelines.org.uk/docs/pdfs/nbtc_bbt_o_neg_red_cells_recs_09_04.pdf|archive-date=29 April 2012}} A potentially fatal reaction is possible if the recipient has pre-existing antibodies, and uncross matched blood is only used in dire circumstances. Since O negative blood is not common, other blood types may be used if the situation is desperate.{{citation needed|date=June 2022}}

File:Ministra Vallejo junto a la Subsecretaria de Salud Pública Andrea Albagli visitaron la Casa del Donante. (53353217903) (cropped).jpg donating blood]]

Red blood cell concentrates are produced either from whole blood or by apheresis. Production from whole blood is far more common than apheresis due to collection and production efficacy as well as economical purposes. When red blood cell concentrates are produced from whole blood, the whole blood is first separated through centrifugation (usually between 3000 to 5000 x g). The red blood cells are denser than plasma and the other present blood cells (platelets, white blood cells) and settle at the bottom of the blood bag. After centrifugation, the red blood cells are separated from the other components (the majority of the plasma, platelets and white blood cells) through the use of an extractor (also referred to as blood press).

After extraction, an additive solution is usually added in a ratio of 1:1.5 to 1:2. The purpose of the additive solution is to maintain adequate viscosity, provide nutrients and ATP/GTP building blocks and reduce haemolysis generation throughout blood bank storage. Choice of additive solution has an impact on the red blood cell viability and, thereby, shelf life (expiry date) of the red blood cell concentrate. Usually, shelf life is limited to 4 to 6 weeks, provided that the red blood cell concentrates are stored in adequate conditions (2-6 °C).  Commercial additive solutions are typically based on saline. They usually contain glucose, adenine, mannitol and, sometimes, phosphate and guanosine.{{cite journal | vauthors = Klei TR, Begue S, Lotens A, Sigurjónsson ÓE, Wiltshire MD, George C, van den Burg PJ, Evans R, Larsson L, Thomas S, Najdovski T, Handke W, Eronen J, Mallas B, de Korte D | title = Recommendations for in vitro evaluation of blood components collected, prepared and stored in non-DEHP medical devices | journal = Vox Sanguinis | volume = 118 | issue = 2 | pages = 165–177 | date = February 2023 | pmid = 36510371 | doi = 10.1111/vox.13384 | hdl = 20.500.11815/4068 | hdl-access = free }} The additive solution has no, or very little, buffering capacity, but buffering is provided by the red blood cells themselves. Traditional additive solutions are hypotonic, although experiments with next-generation additive solutions suggest that an alkali pH in combination with low chloride concentrations may be able to prolong the red blood cell viability.{{cite journal | vauthors = Lagerberg JW, Korsten H, Van Der Meer PF, De Korte D | title = Prevention of red cell storage lesion: a comparison of five different additive solutions | journal = Blood Transfusion = Trasfusione del Sangue | volume = 15 | issue = 5 | pages = 456–462 | date = September 2017 | pmid = 28488968 | pmc = 5589708 | doi = 10.2450/2017.0371-16 }}

Leucocyte depletion of blood components, including red blood cell concentrates, is increasingly becoming standard practise; in many of the high-income countries of the world, 100% of the red blood cell supply is already being leucocyte depleted.{{cite web | title = Blood safety and availability | url = https://www.who.int/news-room/fact-sheets/detail/blood-safety-and-availability | date = 2 June 2023 | publisher = World Health Organization | work = Fact Sheet }} Leucocyte depletion, usually by a leucocyte filter included in the blood bag system, is an efficient yet relatively cheap way of reducing the risk of transfusion reactions. Leucocyte depletion is most commonly performed as an integrated processing step, as bedside filtration is considered a less efficient method.{{cite journal | vauthors = Kopolovic I, Ostro J, Tsubota H, Lin Y, Cserti-Gazdewich CM, Messner HA, Keir AK, DenHollander N, Dzik WS, Callum J | title = A systematic review of transfusion-associated graft-versus-host disease | journal = Blood | volume = 126 | issue = 3 | pages = 406–414 | date = July 2015 | pmid = 25931584 | doi = 10.1182/blood-2015-01-620872 }}{{cite journal | vauthors = Williamson LM, Stainsby D, Jones H, Love E, Chapman CE, Navarrete C, Lucas G, Beatty C, Casbard A, Cohen H | title = The impact of universal leukodepletion of the blood supply on hemovigilance reports of posttransfusion purpura and transfusion-associated graft-versus-host disease | journal = Transfusion | volume = 47 | issue = 8 | pages = 1455–1467 | date = August 2007 | pmid = 17655590 | doi = 10.1111/j.1537-2995.2007.01281.x }}

Red blood cell concentrates are sometimes modified to address specific needs of patients who, for different reasons, are unable to tolerate standard red blood cell concentrates.

Even after leucocyte filtration, a residual number of leucocytes remain in the red blood cell concentrate (<1 million per unit).{{cite book | vauthors = Uerpmann-Wittzack R | chapter = European Directorate for the Quality of Medicines and Healthcare (EDQM) |date=2017-03-09 | title = The Council of Europe |pages=394–406 |publisher=Oxford University Press |doi=10.1093/law/9780199672523.003.0015 |isbn=978-0-19-967252-3}} These may be harmful for patients who have an impaired, reduced or not yet fully developed immune system, or if the blood donor and recipient are closely related. Therefore, such patients may be issued irradiated blood components, including irradiated red blood cells.{{cite journal | vauthors = Moroff G, Luban NL | title = Prevention of transfusion-associated graft-versus-host disease | journal = Transfusion | volume = 32 | issue = 2 | pages = 102–103 | date = February 1992 | pmid = 1542914 | doi = 10.1046/j.1537-2995.1992.32292180135.x }}{{cite journal | vauthors = Foukaneli T, Kerr P, Bolton-Maggs PH, Cardigan R, Coles A, Gennery A, Jane D, Kumararatne D, Manson A, New HV, Torpey N | title = Guidelines on the use of irradiated blood components | journal = British Journal of Haematology | volume = 191 | issue = 5 | pages = 704–724 | date = December 2020 | pmid = 32808674 | doi = 10.1111/bjh.17015 }} X-ray or gamma sources are usually used for irradiation. When blood components are irradiated, the DNA is destroyed in any remaining white blood cells (leucocytes), which stops the leucocytes from being able to proliferate further. Although efficient in reducing the risk of transfusion reactions including fatal transfusion-associated graft-versus-host disease (TA-GvHD), irradiation is damaging to the red blood cell membrane, which can be seen as increased levels of haemolysis during storage. As a consequence, irradiated red blood cell concentrates are usually given a reduced shelf life. Therefore, irradiation of red blood cell concentrates is commonly only performed on demand or for specific parts of the supply.{{cite journal | vauthors = de Oliveira GC, Maia GA, Cortes VF, Santos H, Moreira LM, Barbosa LA | title = The effect of γ-radiation on the hemoglobin of stored red blood cells: the involvement of oxidative stress in hemoglobin conformation | journal = Annals of Hematology | volume = 92 | issue = 7 | pages = 899–906 | date = July 2013 | pmid = 23494204 | doi = 10.1007/s00277-013-1719-z }}{{cite journal | vauthors = Qadri SM, Chen D, Schubert P, Devine DV, Sheffield WP | title = Early γ-irradiation and subsequent storage of red cells in SAG-M additive solution potentiate energy imbalance, microvesiculation and susceptibility to stress-induced apoptotic cell death | journal = Vox Sanguinis | volume = 112 | issue = 5 | pages = 480–483 | date = July 2017 | pmid = 28378415 | doi = 10.1111/vox.12518 }}{{cite journal | vauthors = Serrano K, Chen D, Hansen AL, Levin E, Turner TR, Kurach JD, Acker JP, Devine DV | title = The effect of timing of gamma-irradiation on hemolysis and potassium release in leukoreduced red cell concentrates stored in SAGM | journal = Vox Sanguinis | volume = 106 | issue = 4 | pages = 379–381 | date = May 2014 | pmid = 24330144 | doi = 10.1111/vox.12112 }}

Red blood cell concentrates still contain a small amount of plasma after standard processing (usually 10-15 mL). In order to reduce the risk of allergic reactions to plasma proteins, or to modify the red blood cell concentrates for patients who are sensitive to IgA or potassium ions (K⁺), the red blood cell concentrates can be washed.{{cite journal | vauthors = Davenport RD, Burnie KL, Barr RM | title = Transfusion management of patients with IgA deficiency and anti-IgA during liver transplantation | journal = Vox Sanguinis | volume = 63 | issue = 4 | pages = 247–250 | date = November 1992 | pmid = 1481472 | doi = 10.1111/j.1423-0410.1992.tb01229.x | hdl = 2027.42/74856 | hdl-access = free }}{{cite journal | vauthors = Tóth CB, Kramer J, Pinter J, Thék M, Szabó JE | title = IgA content of washed red blood cell concentrates | journal = Vox Sanguinis | volume = 74 | issue = 1 | pages = 13–14 | date = January 1998 | pmid = 9481854 | doi = 10.1046/j.1423-0410.1998.7410013.x }} Washing typically consists of diluting the red blood cells in saline-based washing solution or red blood cell additive solutions and then washing away any remaining plasma and debris during one or several centrifugation cycles. The process can be performed manually, or with an automated cell washer or processor.{{cite journal | vauthors = Proffitt S, Curnow E, Brown C, Bashir S, Cardigan R | title = Comparison of automated and manual methods for washing red blood cells | journal = Transfusion | volume = 58 | issue = 9 | pages = 2208–2216 | date = September 2018 | pmid = 30204951 | doi = 10.1111/trf.14781 }}

To increase the availability of RBCs of rare blood types, red blood cells can be stored cryopreserved (frozen) instead of refrigerated. With a controlled, standardised freezing and thawing process, the red blood cells can be stored in frozen condition for up to 30 years.{{Cite book |title=AABB. Technical Manual |year=2023 |isbn=978-1-56395-464-1 |edition=21st}} Also for cryopreservation, cell processors are frequently used for both the pre-freezing glycerolisation procedure and for washing away the glycerol after thawing of the red blood cells. Using an automated device allows for standardised processing to ensure optimal protection from ice crystal formation, which otherwise could damage the red blood cells.{{cite journal | vauthors = Yavin S, Arav A | title = Measurement of essential physical properties of vitrification solutions | journal = Theriogenology | volume = 67 | issue = 1 | pages = 81–89 | date = January 2007 | pmid = 17070573 | doi = 10.1016/j.theriogenology.2006.09.029 }}

There are two general approaches for RBC cryopreservation, referred to as the high- and the low-glycerol method. Glycerol serves as cryoprotectant in both. The high-glycerol method uses 40% weight/volume glycerol, a slow freezing rate (1–3 °C per minute) and allows storage of the frozen red blood cells in common mechanical −60–80 °C freezers. The low-glycerol method is based on 20% weight/volume glycerol and demands plunge freezing in (−150 °C) liquid nitrogen. Because of the extreme storage temperature, the low-glycerol method is not compatible with the PVC tubes of blood bags. PVC tubes are essential for sterile docking; a technology which maintains a closed system after thawing and, thereby, allows a longer post-thawing shelf-life. Because of this, and also because the high-glycerol method seems to protect the red blood cells better and is associated with less haemolysis than the low-glycerol method, the high-glycerol method is often preferred.{{cite journal | vauthors = Lelkens CC, Noorman F, Koning JG, Truijens-de Lange R, Stekkinger PS, Bakker JC, Lagerberg JW, Brand A, Verhoeven AJ | title = Stability after thawing of RBCs frozen with the high- and low-glycerol method | journal = Transfusion | volume = 43 | issue = 2 | pages = 157–164 | date = February 2003 | pmid = 12559010 | doi = 10.1046/j.1537-2995.2003.00293.x }}{{cite book | vauthors = Lagerberg JW | chapter = Cryopreservation of Red Blood Cells |date=2015 | title = Cryopreservation and Freeze-Drying Protocols |series=Methods in Molecular Biology |volume=1257 |pages=353–367 | veditors = Wolkers WF, Oldenhof H |chapter-url=http://link.springer.com/10.1007/978-1-4939-2193-5_17 |access-date=2025-01-06 |place=New York, NY |publisher=Springer New York |doi=10.1007/978-1-4939-2193-5_17 | pmid = 25428017 |isbn=978-1-4939-2192-8 }}

Pathogen reduction is a technology predominantly used to reduce the risk of transfusion-transmitted infectious diseases and bacterial contamination. The principle resembles the one of irradiation: by adding an agent which interferes with the replication process of DNA or RNA, any present pathogen, as well as any residual leucocytes, will not be able to replicate further.{{cite journal | vauthors = Henschler R, Seifried E, Mufti N | title = Development of the S-303 Pathogen Inactivation Technology for Red Blood Cell Concentrates | journal = Transfusion Medicine and Hemotherapy | volume = 38 | issue = 1 | pages = 33–42 | date = 2011 | pmid = 21779204 | pmc = 3132978 | doi = 10.1159/000324458 }}{{cite journal | vauthors = Mufti NA, Erickson AC, North AK, Hanson D, Sawyer L, Corash LM, Lin L | title = Treatment of whole blood (WB) and red blood cells (RBC) with S-303 inactivates pathogens and retains in vitro quality of stored RBC | journal = Biologicals | volume = 38 | issue = 1 | pages = 14–19 | date = January 2010 | pmid = 19995680 | doi = 10.1016/j.biologicals.2009.10.019 }}

Systems for pathogen inactivation of red blood cells are still awaiting market authorisation. However, studies suggest that the red blood cell quality is not negatively impacted by this processing procedure, which indicates that pathogen inactivation may be a suitable future substitute for irradiation and potentially also washing of red blood cells.{{cite journal | vauthors = Cancelas JA, Gottschall JL, Rugg N, Graminske S, Schott MA, North A, Huang N, Mufti N, Erickson A, Rico S, Corash L | title = Red blood cell concentrates treated with the amustaline (S-303) pathogen reduction system and stored for 35 days retain post-transfusion viability: results of a two-centre study | journal = Vox Sanguinis | volume = 112 | issue = 3 | pages = 210–218 | date = April 2017 | pmid = 28220519 | doi = 10.1111/vox.12500 | doi-access = free }}{{cite journal | vauthors = Larsson L, Ohlsson S, Andersson TN, Watz E, Larsson S, Sandgren P, Uhlin M | title = Pathogen reduced red blood cells as an alternative to irradiated and washed components with potential for up to 42 days storage | journal = Blood Transfusion = Trasfusione del Sangue | volume = 22 | issue = 2 | pages = 130–139 | date = March 2024 | pmid = 37458715 | doi = 10.2450/BloodTransfus.479 | pmc = 10920064 }}

Red blood cell rejuvenation is a method which aims to increase the levels of 2,3-diphosphoglycerate (2,3-DPG) and ATP in stored red blood cell concentrates, as the levels of both 2,3-DPG and ATP decrease over time. The rejuvenation process includes incubation of the red blood cells with a rejuvenation solution and subsequent washing.{{cite journal | vauthors = Enten G, Dalvi P, Martini N, Kausch K, Gray A, Landrigan M, Mangar D, Camporesi E | title = Rapid bedside rejuvenation of red blood cell with an autologous cell salvage device | journal = Vox Sanguinis | volume = 113 | issue = 6 | pages = 562–568 | date = July 2018 | pmid = 29971786 | doi = 10.1111/vox.12671 | doi-access = free }} ATP is an important driver of a number of metabolic functions of the red blood cell, and declined ATP levels have been linked to reduced post-transfusion in vivo survival of the red blood cells. High levels of 2,3-DPG facilitates oxygen unloading from the red blood cells in the capillaries.{{Cite journal | vauthors = Inglut C, Kausch K, Gray A, Landrigan M |date=2016-12-02 |title=Rejuvenation of Stored Red Blood Cells Increases Oxygen Release Capacity |url=https://ashpublications.org/blood/article/128/22/4808/99780/Rejuvenation-of-Stored-Red-Blood-Cells-Increases |journal=Blood |language=en |volume=128 |issue=22 |pages=4808 |doi=10.1182/blood.V128.22.4808.4808 |issn=0006-4971|url-access=subscription }}

Red blood cell concentrates can be modified to be suitable for paediatric patients. These modifications include split of regular units into smaller units (usually 3 – 6 parts), which facilitates limiting the number of involved donors at repeated transfusions. The modification can also be red blood cells for intrauterine transfusion where, in short, the additive solution is removed, which increases the haematocrit to between 0.70 – 0.85. A red blood cell concentrate can also be tailored for exchange transfusions for neonates. During this process, the additive solution is removed and instead, plasma is added to resemble a “whole blood”. Both at intrauterine and exchange transfusion, compatibility between the foetus/baby and the mother is of great importance.

Adverse events related to transfusion in general may include allergic reactions such as anaphylaxis, infection, volume overload, and lung injury.  With current screening methods, the risk of viral infections such as hepatitis C and HIV/AIDS are less than one in a million. With current testing methods in high-income countries the  prevalence of transfusion-transmissible infections in blood donations is very low (median: HIV 0.002%, hepatitis B 0.02%, hepatitis C 0.007% and syphilis 0.02% in 2024). However, in low-income countries the risk of a blood donation being positive for HIV, hepatitis C or syphilis is up to 1%, and the risk of it being hepatitis B positive was approximately 2.8% in 2024.  The differences relate to variations in eligible blood donors, whether the donation is paid or voluntary, non-remunerated, and the effectiveness of the system of educating and selecting donors.{{Cite book |url=https://books.google.com/books?id=YnsOEQAAQBAJ&q=%22Blood+safety+and+availability%22.+WHO+fact+sheet&pg=PR6 |title=Guidance on ensuring a sufficient supply of safe blood and blood components during emergencies |date=2023-04-14 |publisher=World Health Organization |isbn=978-92-4-006863-6 |language=en}}

Adverse events related to transfusion of red blood cells are mainly linked to incompatibility issues or other transfusion reactions. Incompatible AB0 transfusion can be fatal.{{Cite journal | vauthors = Maxwell MJ, Wilson MJ |date=December 2006 |title=Complications of blood transfusion |journal=Continuing Education in Anaesthesia Critical Care & Pain |volume=6 |issue=6 |pages=225–229 |doi=10.1093/bjaceaccp/mkl053 |issn=1743-1816}} For patients with a previous transfusion reaction history, the risk of repeated adverse events can be mitigated by choosing the proper processing modification and/or red blood cell phenotype combination.

In the United Kingdom they cost about £120 per unit.{{cite book| vauthors = Yentis SM, Hirsch NP, Ip J |title=Anaesthesia and Intensive Care A-Z: An Encyclopedia of Principles and Practice|date=2013|publisher=Elsevier Health Sciences |isbn=9780702053757 |page=147 |url=https://books.google.com/books?id=Te7TAAAAQBAJ&pg=PA147 |language=en|url-status=live|archive-url=https://web.archive.org/web/20170112190224/https://books.google.ca/books?id=Te7TAAAAQBAJ&pg=PA147|archive-date=2017-01-12}}

The product is typically abbreviated RBC, pRBC, PRBC, sometimes StRBC, or even LRBC (the latter being to indicate those that have been leukoreduced, which is now true for the vast majority of RBC units). The name "Red Blood Cells" with initial capitals indicates a standardized blood product in the United States.{{cite web |url=http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=640 |title=21 CFR 640.10|publisher=GPO |access-date=3 November 2011|url-status=dead|archive-url=https://web.archive.org/web/20111026103821/http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=640 |archive-date=26 October 2011}} Without capitalization, it is simply generic without specifying whether or not the cells comprise a blood product, patient blood, etc. (with other generic terms for it being "erythrocyte" and "red cell").{{citation needed|date=June 2022}}

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