Practical Procedures
Blood transfusion: a practical guide
Introduction longer for people with rarer blood groups,
Over 2 million units of red cells are trans- Table 1. ABO blood group people who have received many transfusions
fused in the UK every year, half of which characteristics or who have developed antibodies. In emer-
are used for surgical patients. A successful gencies ABO-group specific blood (12 min-
transfusion is the appropriate provision of ABO blood utes to issue) or group O blood (which has
blood cells or other blood components in a group and Antigens Antibodies neither A nor B antigens) may be necessary.
safe and timely manner. This article gives a UK incidence on RBCs in serum Notes
practical guide to transfusion medicine. A (42%) A Anti-B Blood components, indications
and guidelines
Blood groups B (8%) B Anti-A All blood components produced in the
The most important blood group is the AB (3%) A and B Neither ‘Universal UK are filtered to remove white cells.
ABO system because of the natural expres- recipient’
sion of antibodies to A and B in individu- O (47%) Neither Anti-A and ‘Universal Whole blood
als who do not have these antigens (Table anti-B donor’ This is very rarely used.
1). If an individual receives cells with anti- RBC =red blood cells
gens recognized by the recipients’ antibod- Red cells
ies (e.g. group B recipient receiving group blood units with the patient’s blood to see Each 250–350 ml bag has a haematocrit
A red cells) these donor cells are identified if any abnormal reaction occurs. A group (% of cells) of 0.6. There are no platelets,
as foreign and attacked, resulting in a and save should be ordered if the patient is very few white cells and 2,3-diphospoglyc-
severe haemolytic transfusion reaction. unlikely to need a blood transfusion but it erate (2,3 DPG) levels remain normal for
will reduce the time required for cross- up to 14 days, allowing relatively normal
Donor selection matched blood, should the patient subse- oxygen uptake and release by haemoglob-
Stringent criteria are in place to limit the quently need it. If the patient needs blood, in. Red cell preparations may be stored for
chance of a donor with a transmissible you should crossmatch the number of 42 days with SAGM (saline, adenine, glu-
infection giving blood. Each unit is screened units they will need. As a general rule, one cose, mannitol) solution at 40°C but must
for evidence of infection with syphilis, unit of blood raises the haemoglobin by be used within 6 hours at room tempera-
hepatitis B and C, the human immunode- 1 g/dl in the non-bleeding adult patient. ture. Current guidelines suggest a haemo-
ficiency virus (HIV) 1 and 2, human T-cell For elective surgery, the case should be globin transfusion threshold in stable
lymphotropic viruses 1 and 2 and in some discussed with the anaesthetist and sur- patients of 8 g/dl, or 10 g/dl in patients
instances cytomegalovirus, malaria, West geon, who will take into account the pre- with cardiorespiratory disease.
Nile virus and Trypanosoma cruzi. operative haemoglobin, the likely blood
loss and the patient’s tolerance for anaemia. Platelets
Ordering blood: the practicalities In an emergency, liaise with the transfusion In the UK, platelets either come from pool-
As severe reactions result from human laboratory early: each hospital will have its ing of the platelet component from four
error, great care must be taken to ensure own policy for crossmatching and treat- units of whole donated blood, called ran-
the correct blood reaches the right patient, ment of major haemorrhage (Table 2). dom donor platelets, or by plasmapharesis
including labelling of blood samples sent As there are more than 12 blood group from a single donor. The platelets are sus-
to the laboratory. A group and save involves systems (e.g. ABO, Rhesus, Kell, Duffy pended in 200–300 ml of plasma and may
determining the patient’s ABO blood Kidd, Diego MNS) it takes about 40 min- be stored for up to 4 days in the transfusion
group and screening serum for the presence utes to determine an individual’s blood laboratory where they are continually agi-
of antibodies to common red cell antigens group (group and save) and 40 minutes to tated at 22°C to preserve function. One
that can cause transfusion reactions. crossmatch (issue) blood. This may take adult platelet pool raises the normal platelet
In addition to this, crossmatching
involves the mixing of samples from donor
Table 2. Suggested blood requirements for elective surgical procedures
Dr Edward Burdett is Specialist Registrar
in Intensive Care Medicine, Barnet District Need for Approximate Suggested
General Hospital, London and Dr Robert transfusion blood loss action Surgery
Stephens is Academy of Medical Sciences/the Unlikely 3000 ml XM 6+ units Cystectomy, elective AAA repair
Correspondence to: Dr R Stephens AAA= abdominal aortic aneurysm; ERPC= evacuation of retained products of conception; TURP= transurethral resection of the prostate; XM=cross match
British Journal of Hospital Medicine, April 2006, Vol 67, No 4 M67
Practical Procedures Practical Procedures
unit contains 20–40 ml (although larger incompatible blood may cause local symp-
Table 3. Indication for platelet bags may be available) and should be ABO toms within seconds, which is why patients Table 7. Complications of massive Table 9. Alternatives to transfusion
transfusion compatible with the patient. The main should be closely observed at the start of blood transfusion
indication for cryoprecipitate is hypofi- each transfusion (Tables 5 and 6). Technique Description
Threshold Indication brinogenaemia, either as a result of massive Since it may be impossible to identify Impaired oxygen delivery as a result of lack of Reduction in blood loss Induced hypotension, improved haemostasis during surgery
Absolute number Bleeding in a patient with transfusion or disseminated intravascular immediately the cause of a severe reaction, 2,3-diphosphoglycerate Autologous blood transfusion The patient receiving their own blood, donated weeks before surgery
not important impaired platelet function coagulation (DIC). Treatment is consid- the initial management is supportive. Hypothermia
ered if the plasma fibrinogen is <0.8–1 g/ Cell salvage Machine that collects, ‘cleans’ and re-infuses the patient’s blood during
(e.g. aspirin therapy) Coagulopathy and/or after surgery
litre; ten units of cryoprecipitate should Bacterial contamination of blood
Platelets <10x109/litre In a clinically stable patient Transfusion-related acute lung injury Erythropoetin Recombinant hormone that promotes red cell production
increase fibrinogen level by 1 g/litre. components
Platelets <50x109/litre Critically ill patient, This is the commonest infective hazard of Hypocalcaemia Purified haemoglobin Expired or animal blood and/or red cell membrane substitute, e.g. a liposome
coagulopathy, undergoing Hazards of transfusion blood component transfusion. Clinically it
invasive procedure, Hyperkalaemia Recombinant haemoglobin From bacteria
bleeding
Acute hazards causes a rapid onset of sepis: fever, tachy-
Acidosis Perfluorocarbons Inert oxygen-carrying chemicals
Serious or life-threatening reactions to cardia, hypotension, rigors and collapse.
count (150–450 platelets x 109/litre) by transfusion are very rare. However, new trates. The treatment is that for adult respi- Iron overload lines at a national and local level. Where
5–10 platelets x 109/litre (Table 3). symptoms or signs that arise during a trans- Transfusion-related acute lung injury ratory distress syndrome. Most authorities Repeated transfusions for chronic anaemia, possible, transfusion practice should be
ABO identical or compatible platelets fusion must be taken seriously. Over half of TRALI is related to the presence of anti- believe this condition, which has a mortal- for example thalassaemia, may result in audited, and transfusion-avoidance strate-
are preferred but not necessary in adults; serious transfusion reactions are caused by bodies in donor plasma to the recipient’s ity of up to 30%, is under-recognized. iron deposition in the tissues and organ gies used. BJHM
but rhesus compatibility is required in administrative errors: patients being trans- leucocytes. It is most common in individu- injury. This is treated by prophylaxis with
The authors would like to thank Dr Patricia Hewitt and
recipients who are children and women of fused blood that had been intended for als who have had large doses of FFP. Fluid overload the iron binding agent desferrioxamine.
Dr Mike James for their generous advice.
childbearing age to prevent haemolytic another patient. Other common acute Clinically, transfusion is followed by rapid Excess or over-rapid transfusion may result Conflict of interest: none.
disease of the newborn. effects include less severe immune reac- onset of hypoxia, respiratory difficulties in acute left ventricular failure, with signs of Immunosuppression
tions, fluid overload, transfusion associated and a non-productive cough. The chest X- pulmonary oedema. The transfusion should There is some evidence that transfusion Further reading
Hebert PC (1998) Transfusion requirements in
Fresh frozen plasma lung injury (TRALI), and transfusion of ray characteristically shows bilateral infil- be stopped and steps to relieve the pulmo- around the time of surgery may be associ- critical care (TRICC): a multicentre, randomized,
Fresh frozen plasma (FFP) is produced bacterially infected components. nary oedema should be given, including ated with a greater risk of postoperative controlled clinical study. Transfusion
from centrifugation of whole donated Table 5. Signs and symptoms of diuretics and oxygen. Massive blood trans- infections and tumour recurrence in cancer Requirements in Critical Care Investigators and
the Canadian Critical care Trials Group. Br J
blood, or plasmapheresis. Each 150 ml Severe immune transfusion reactions severe immune transfusion reactions fusion is the acute administration of more patients, but this is controversial. Anaesth 81 (Suppl 1): 25–33
bag contains all clotting factors, albumin This includes acute haemolytic transfusion than 1.5 times the patient’s blood volume, Murphy MF, Wallington TB, Kelsey P et al (2001)
and antibodies. FFP must be used imme- reactions (such as ABO incompatibility) Symptoms Feeling of apprehension or or replacement of the patient’s total blood Alternatives to allogenic blood Guidelines for the clinical use of red cell
diately after thawing and must be ABO and immune reactions to other blood com- ‘something wrong’ volume within 24 hours. transfusion transfusions. Br J Haematol 113: 24–31
compatible. The usual starting dose is ponents such as platelets and white cells. The expense and side-effects of transfusion Internet resources
Flushing
10–15 ml/kg, equivalent to three or four ABO incompatibility can destroy red cells Long-term hazards has led to the search for alternatives, some British Blood Transfusion Society: www.bbts.org.uk
packs of FFP for a 70 kg person (Table 4). in the circulation, cause circulatory and Pain at venepuncture site Risk of infectious disease of which are clinically established and National Blood Service: www.blood.co.uk
Serious Hazards of Transfusion (SHOT): www.
Because of the potential risk of variant respiratory collapse, initiate acute renal Pain in abdomen or chest Because of donor selection and screening some still in development (Table 9). Many shotuk.org
Creutzfeldt–Jakob disease (vCJD) in UK failure and cause DIC. It has been sug- techniques, the risk of transmission of of these are only appropriate for elective, UK Blood Transfusion and Tissue Transplantation
Signs Fever Services: www.transfusionguidelines.org.uk
donors, FFP for children born after 1995 gested that a single practitioner taking infectious disease is very rare for red cell, planned surgery.
is derived from unpaid USA donors. overall responsibility for checking the blood Hypotension FFP and cryoprecipitate transfusions (Table
and patient before transfusion is safer than Generalized oozing from wounds or 8). A figure for platelet transfusions is more Social implications of blood KEY POINTS
Cryoprecipitate two practitioners checking. If red cells are puncture sites difficult as single platelet donors are more transfusion
Cryoprecipitate is precipitated from FFP, mistakenly administered to the wrong Haemoglobinuria regularly tested, whereas platelet pools are A blood transfusion is a procedure with n All blood product component transfusions
and contains high levels of factor VIII, patient, the chance of ABO incompatibili- derived from four donors. potential complications: many patients have risks.
Respiratory distress
fibrinogen and von Willebrand factor. Each ty is about 1 in 3. Even a few drops of ABO Two cases of vCJD transmission by would prefer not to be transfused if at all n Great care should be taken to ensure the
blood transfusion have been reported in possible. Jehovah’s witnesses refuse all blood correct blood reaches the right patient.
Table 4. Indications for fresh frozen Table 6. Initial management of suspected acute transfusion reaction the UK along with another of vCJD ‘infec- products, but may allow blood to be re-
n Modern evidence suggests a transfusion
plasma tivity’: the recipient died of other causes transfused if it has not lost contact with the
trigger of haemoglobin<8 g/dl in most
Stop the transfusion – keep the IV line open with saline or Hartmann’s solution but had evidence of abnormal prion pro- circulation such as during cardiopulmo-
Recheck the blood/patient compatibility tein at post mortem. nary bypass. patients.
Severe traumatic or surgical bleeding with large
packed red cell requirement Check the patient’s temperature, blood pressure, pulse, respiratory rate: if these are abnormal check the It is advisable to obtain and record a n Blood products components such as fresh
arterial blood gases and oxygen saturation Table 8. Approximate incidence of patient’s consent for blood transfusion, frozen plasma and cryoprecipitate have
Plasma exchange
especially if they may receive blood while limited indications.
Single or multiple factor deficiency in the absence Give paracetamol 1 g iv/po for fever and antihistamine (e.g. chlorpheniramine 10 mg iv) for urticaria viral infection after transfusion in UK
under anaesthetic.
of a recombinant alternative Adrenaline (0.3–0.5 mg im) may be needed for circulatory collapse n Blood use should be audited at a local
Infection Risk and national level.
Disseminated intravascular coagulation with Notify blood bank; keep blood bag Conclusions
bleeding Human immunodeficiency virus 1 in 5 million Blood transfusion is an essential part of n There are many established and
If reaction is mild, slowly re-commence transfusion
Warfarin overdose with severe bleeding Hepatitis B 2 in 1 million acute medical care, but it has side effects. experimental strategies to minimize the
If severe: call for senior help, and consider referral to intensive care need for transfusion.
Liver disease with a prolonged prothrombin time Hepatitis C 1 in 30 million Modern practise emphasizes the rationali-
IM= intramuscular; IV = intravascular; PO= oral zation of transfusion according to guide-
M68 British Journal of Hospital Medicine, April 2006, Vol 67, No 4 British Journal of Hospital Medicine, April 2006, Vol 67, No 4 M69