A presentation on essential element and components of blood needed in transfusion medicine. Lectures aims to familiarize the benefits of individual blood components

1. BLOOD TRANSFUSION
F.A. Uba MD

2. Introduction
Transfusion of blood or blood products is an invaluable therapeutic measure. It
should, however, not be given without good reason because of its potential hazards.
Currently whole blood is separated into specific components which can be tailored
to the physiological needs of the patients.
Safe transfusion practice rests on three main pillars - getting blood from a
voluntary altrulsric donor; good quality screening and testing of donated blood:
safe storage and transfusion only when absolutely necessary.

3. Indications for blood products transfusions
1. To increase the oxygen carrying capacity with red cells
2. Enhance primary haemostasis with platelet transfusions
3. Enchance secondary haemostasis with cryoprecipitate and other plasma fractions.

4. Donation and Collection of Blood
Donors,who should be between 18-65 years and over 51kg in weight, should be:
I. Fit i.e.
(1). Haemoglobin of over 12g/dl or more for both males and females.
(ii). No major operation in the last 6 months.
(iii). No pregnancy within the last 12 months.
(iv). No blood donation in the past 4 months
(v). No clinical malaria in the past one month in endemic areas.
(vi). No blood transfusion, tissue or organ transplantation within the past 12 months.

5. (vii). Free from severe hypertension, splenornegaly, hepatomegaly, bleeding
disorder or allergic conditions such as asthma.
(viii). No recent explained weight loss of 4.5kg or more.
(ix). Not had tattoos, ear or skin piercing, acupuncrure or accidental needle-
stick injury within the past 12 months.

6. 2. Free of’ history or clinical evidence and not carriers of the following diseases:
(i) Viral bepatitis
(ii) HIV infection
(iii) Syphilis
(iv) Trypanosomiasis
(v) Brucellosis
The blood should be non-reactive for the VDRL test and negative for hepatitis B
surface antigen (HBsAg), Hepatitis C virus antibody, and H1V I + II antibodies.
Additional screening tests may be done depending on the geographical area, and the
indications for transfusion. These include HTL VI antibody, malaria screening and
CMV antibody. PCR may be used to pick the window period of some infections e.g.

7. 3. Unvaccinated within the last 3 weeks and must not belong to any of the risk
groups for HIV infection e.g. homosexuals, IV. drug abusers or commercial sex
workers and their clients. At best the blood bank should rely on the repeated
altruistic donor whose track record of non- risky life style would have been proven
through repeated negative testing.
Collection of blood should be done under strict asepsis into a sterile plastic bag
containing 60ml of citrate-phosphate- dextrose (CPD) as anticoagulant and
preservative. Citrate- phosphate-dextrose (CPD) keeps U1ered cells viablefor21
days in vitro. The use of CPDA-1, adenine-enriched CPD, extends the shelf-life to
35 days. The labelled plastic bag is stored as early as possible ina special blood
bank refrigerator dedicated for that purpose at 2-6°C.

8. Afterwards the following tests are done on donor blood collected into a separate
container.
1. ABO and Rh grouping
2. Serological tests for syphilis, HBsAg, HCV, HT L VI and HIV I & II. Donated
blood found to be positive for any of the screened markers are discarded.

9. Component Therapy
Indications for the use of whole blood are now limited except in hospitals and areas
where facilities for producing blood components are unavailable. For successful
component preparation, blood must be donated into double, triple or quadruple bags
depending on the number of components to be derived from each unit.

10. 1. Packed RBC: The donated blood is centrifuged at 3000 revs/minor 5000 x g for
5 min and most of the plasma moved into the second bag by a plasma extractor,
to give a Hct of 0.75. Packed cells are for transfusion in all anaemic patients.
One unit raises the Hb by approximately 1g/di in a 70kg adult and washed
packed cells are given to patients awaiting transplantation and those with
known allergic or febrile non- haemolytictransfusion reaction. Rare blood units
can be kept frozen for long term storage if cryopreservatives are added.

11. 2. Platelet concentrate: It is the precipitate after platelet-rich plasma is centrifuged
at 3000 rev/ min or 5000 x g for 5 min. Platelet-rich plasma is the supernatant
plasma after whole blood is centrifuged at 1000rev/minor2000x g for3 min. It is
used in the short-term management of severe or life- threatening thrombocytopaenia
or thrombocytopathy. One unit of platelet concentrate raises the platelet count by
approxi- mately 5-10 x 109/L in an adult. For patients who have developed platelet
antibodies, multiple units derived from an HLA matched donor by plateletpheresis
may be needed. Platelets are stored at room temperature and are kept rotated or
agitated mechanically throughout the storage period of 5 days. This prevents platelet
aggregation and therefore pre- serves their physiological function during storage.

12. 3. Granolocyte concentrate: It is usually prepared by leukopheresis, The volume
is 220ml and contains approximately 1.0 x 1010 granulocytes/unit, It is useful in
selected patients with sepsis and severe neutropaenia. It has to be irradiated to
prevent post transfusion graft-versus-host disease in neonates and immuno-
compromised recipients. The shelf-life is 24h. With the increasing use of
commercially prepared Granulocyte-Colony Stimulating Factors, the usefulness
of granulocyte concentrates isdoubtful.

13. 4. Fresh frozen plasma (FFP): It is the plasma portion that is separated and rapidly
frozen by placing in the freezer within 8h of collection when fresh blood is
centrifuged at 3000 revs/min or 5000 x g for 7min. It contains plasma proteins i.e.
albumin and globulin that maintain oncotic pressure and immunity respectively; all
components of coagulation, fibrinolytic and complement systems, fats, carbo-
hydrates and minerals. FFP is an effective volume expander because of the plasma
proteins and helps in correcting certain disorders of haemostasis. However, because
it can, like other blood products, transmit certain organisms, especially H1V, it is
indicated only when other means of correction of the deficiencies are not available.

14. These indications are:
(i) Deficiencies of coagulation factors or inhibitors of coagulation for which
specific concentrates are not available
(ii) Emergency treatment of warfarin overdosage and Vit. K deficiency when
factor IX complex concentrate is not available.
(iii) Treatmnent of thrombotic thrombocytopaenic purpura.
(iv) Treatmentof'disserninated intravascular coagulation. Platelets and
cryoprecipitate are also very beneficial in such situations.
There is now no justification for using FFP to replace volume, nutrients or
immunoglobulins. FFP is stored at -I8°C and below. The shelf-life is I year.

15. 5. Cryoprecipitate: It is the precipitate when fresh frozen plasma is allowed to
thaw at 4°C and the supernatant plasma removed. It is rich in Factors Vlll and
XIII, fibrinogen and vonWillebrand’s factor and is stored at-40oC. It is used in
haemophilia, hypofibrinogenaemia and vonWillebrand's disease. The volume
of each unit of cryoprecipitate is 15ml and contains 80-100IU of Factor VIII
and a minimum of 150mg of fibrinogen.

16. 6. Other fractions are:
(i) Protein solutions e.g. Human plasma protein fraction, albumin concentrate,
immune and hyperimmune globulins, antithrombin III and protein
concentrate.
The latter two fractions are used to correct hereditary deficiency states which
predispose to thrombophilia.
(ii) Factor concentrates e.g. Factor Vlll, Factor IX complex and fibrinogen.
Although Recombinant factor VIII and IX are available, andare free from disease
transmitted by blood, they are very expensive thus making concentrates still
necessary

17. Effects of Storage of Blood at 2-6°C
Fresh blood, i.e. blood used within 3h of collection, has all its constituents
preserved; platelets, leucocytes, factors V and VIII are all active. However, when
blood is stored at 2-6°C, the following changes occur with time:
1. Red cells: They swell by about 20% and lose potassium gradually to the plasma. But
they regain their potassium within 24h of transfusion. The viability of the cell
diminishes as its ATP and 2,3DPG fall. The survival of the cells after transfusion is
affecced: about 1% of them are lost for every day of storage, Thus, after 20 days only
80 % of the cells stored in ACD survive 24h after transfusion.

18. If the blood is left for a few hours in a warmenvironment, e.g. at 37°C,the
percentage of cells that survive after transfusion is considerably reduced.
After about a week of storage, the level of 2,3 diphosphoglycerate in the cells falls
resulting in increased affinity of haemoglobin for oxygen and depressing oxygen
release at the tissue level. Recovery takes place within 24h after transfusion. But if
large volumes of such blood is given, thepatient’s tissue oxygenation may be
depressed in the initial hours.

19. 1. Leucocytes: They are not viable after 24h of storage. Even fresh leucocytes
survive for only 30-90 min in the recipient's blood.
2. Platelets: There are no viable platelets after 24h storage in the fridge
although non-viable platelets remain for 2 weeks.

20. 4. Electrolyte
(i) Potassium diffuses out of the red cells and the plasma potassium rises at the
rate of about 1mmol/day. Thus, blood stored for 20 days has a plasma potassium
of about 25mmol/l. Massive transfusion of old blood may therefore cause
hyperkalaernia resulting in cardiac arrhythmia or arrest. Therefore blood for
exchange transfusion should not be more than 5 days old.
(ii) The sodium concentration of the plasma is increased because of the sodium
citrate in the CPD anticoagulant.
(iii) Calcium: There is no ionized calcium. Ionized calcium displaces sodium in
di- sodium citrate forming unionized calcium citrate.

21. 5. Clotting Factors:
(i) Factor VIII (AHF) declines rapidly and activity falls by 40% after 24h of
storage and by 75% after 5 days. There is little activity after 7 days.
(ii) Factor V declines rapidly after 24h and there is very little activity after 7
days.
(iii) Factor IX declines rapidly after 7 days and there is no activity after 14
days.
(iv) Factor X loses its activity after 7 days.
(v) Factor VII declinesonlyafter 14days.
(vi) Fibrinogen and factor II are stable for 21 days.

22. 6. pH: The lactic acid concentration rises from continuing red cell glycolysis
and the pH falls from about 7.2 at the time of collection to about 6.8 at 20
days.
7. Plasma haemoglobin levels rise during storage due to leakage of Hb from
cells. At 20 days the level is about 0.2 g/ L
8. The ammonia concentration also rises.

23. Blood Groups and Compatibility
The important blood groups for transfusion purposesare A, B, AB and O . There is
also the D (Rh+ ) antigen which is present in 85 % of Caucasians and 95 % of Black
Africans. Those without the D antigen may develop antibodies to it if they are
transfused with D positive blood or carry a D positive fetus. Reactionmay then
occur at subsequent transfusion with D positive blood.
There are other antigens which are of less clinical importance e.g. Kell, Lewis,
Duffy, MNS, Kidd etc., but antibodies to them may develop in multiply transfused
patients or multiparous women. ABO and Rh compatible blood should always be
cross-matched with the recipient's serum before use to avoid serious adverse
antigen-antibody reactions of incompatibility.

24. Compatibility testing has undergone various modifications. The method
recommended by the AA BB is outlined below:
1. To detect saline-reacting antibodies or ABO incompatibility, 2 drops of the
patient’s serum are added to 1 drop of a 4 % saline suspension of donor's red cells
in a labelled test tube. The contents are mixed and then centrifuged for 15-20
seconds at approximately 900 to1000 x g. The tube is examined for haemolysis and
the red cell button is gently resuspended and examined for agglutination.
Agglutination or haemolysis indicates incompatibility. If the test is negative, then
one proceeds cothe next stage.

25. 2. Detection of warm or albumin reacting antibodies. Two drops of 30% bovine
albumin is added to the resuspended red cell sand mixed. The tube is then
incubated at.37°C for 30 minutes and then centrifuged for 15-20 seconds. The
tube is again examined for haemolysis and agglutination as before. A positive
result indicates incompatibility. If the test is negative, then one proceeds to the
next stage.

26. 3. The red cell suspension is washed 3 or 4 times with saline and the final wash is
completely decanted. Anti-human globulin is added and mixed well with the red
cell button according to the manufacturer's instructions. The tube is centrifuged
again and the reaction observed. The presenceof agglutination indicates
incompatibility. Negative results should be confirmed by adding IgG-coated
(sensitized) red cells. The donor blood is declared compatible if this fina ltest
confirms the negative result.

27. The AA BB advocates antibody screening before the crossmatch for patients who
need blood transfusion. The patient's serumis testedwithcommerciallyprepared
redcells which express all the clinically relevant antigens. The procedure is similar
to that outlined above. If the test is positive, the laboratory then proceeds to find the
antibody present and antigen negative donor cells are then used for the crossmatch.
Some laboratories advocate the abbreviated crossmatch when the antibody
screen test is negative. Steps 2 and 3 above are the nomitted. Lt has been found to
be 99.99% safe and saves on reagent costs. Eletronic issue of blood is also
available, it requires no testing.

28. Future trend: Following research on some bacteria, enzymes have been found
that neutralise or destroy the complex oligosaccharides on the red cell membrane
that forms its characteristic A, B, or AB antigen. It is therefore going to be
possible in the near future to use all blood groups as universal donors and not
only Group O as they will all be rendered compatible.

29. Administration and Rate of Blood Transfusion
Blood to be transfused should always be identified and checked against the
recipient's name, gr oup, hospital number and ward. The drip is set up under strict
asepsis using a 17- gauge or large needle. Untoward symptoms usually occur
during infusion of the initial 100ml. The rate should therefore initially be 20-30
drops. i.e. 2-3ml/min. It is increased after half an hour to 60-80 drops/min. If there
is blood loss the rate of infusion should be rapid, squeezing if necessary the plastic
bag containing the blood. In the elderly and the very young, the rate should be
slow - about 40 drops or less/min. The patient's general condition, pulse and BP
should be monitored throughout.

30. COMPLICATIONS AND HAZARDS OF BLOOD TRANSFUSION
These complications and hazards may be due to a number of reasons. Most of them
are immune-related ranging from mild (urticaria) to severe (haemolytic)and some
may be due to human error. Because of the incidence of these errors, the Serious
Hazards of Transfusion Scheme (SHOT) was formed in the UK in 1996 to monitor
all such incidences. A hazard is defined as "any unfavourable event occurring in a
patient during or following the transfusion of blood or a blood product".
Traditionally, transfusion reactions may be immediate or delayed (Table below).

31. Table
A. IMMEDIATE REACTIONS
1. Febrile non-haemolytic reaction
2. Allergic and anaphylactic reaction
3. Haemolytic reaction
4. Bacterial contamination
5. Circulatory overload
6. Cardiac arrest
7. Air embolism
8. Non-cardiogenic pulmonary oedema (Transfusion related acute lung injury).

32. (iv) Cytomegalovirus infection
(v) Trypanosomiasis
(vi) Toxoplasmosis, brucellosis
(vii) Variant Creutzfeldt-Jacob Disease (vCJD)
(viii) AIDS
(ix) Parvovirus
5. Iron overload (Transfusion haemosiderosis)
6. Immunosuppression. Due probably to
transfused leucocytes
7. Post-transfusion graft-versus-hostdisease
B. DELAYED REACTIONS
l . Thrombophlebitis
2. Delayed haemolytic reaction
3. Post-transfusion tbrombo-
cytopaenic purpura
4. Transmissionof diseases:
(i) Viral Hepatitis A, B, C, D
(ii) Malaria
(iii) Syphilis

33. A. IMMEDI ATE REACTIONS
1. Febrile non-haemolytic transfusion reaction
It is quite common and most often due to incompatibility between antigens on the
donor white cells and antibodies in the recipient's plasma formed as aresult of
previous transfusions orpregnancies. It may also be due to endotoxin or pyrogens in
the transfusion set or blood. But these have been virtually eliminated bycurrent
technology and quality control of water used in preparing the anticoagulams.
Thef eatures are:
(i) Rigors and fever
(ii) Nausea and vomiting

34. Management
The transfusion is stopped temporarily, and it is expected that the condition settles
after a few hours. If not, it is investigated to exclude a haemolytic reaction,
septicaemia or malaria (see below). Aspirin or paracetamol brings down the
temperature. Future transfusions in such individuals and infact all persons should be
with leucocyte-depleted blood products by the use of appropriate filters.

35. 2. Allergic Reaction (These reactions are mediated by histamines and leukotrienes).
It occurs in 2% of transfusions and a few maybe occasionally fatal. It is more common
in patients receiving repeated transfusions and those with IgA deficiency. It is due to
allergens, usually plasma proteins, inthedonor plasma and so is less likely to occur with
packed red cells. Symptoms which maybeacuteor delayed are.-
(i) Urticaria.
(ii) Myalgia and arlhralgia.
(iii) Bronchospasm, oedema of the face and/orlarynx, in severe cases with anaphylaxis.
(iv) Chest pain, hypotension, abdominal cramps, diarrhoea and shock in cases with
anaphylaxis
(v) Pyrexia

36. Management
(i) The transfusion should be interrupted and antihistamine and corticosteroid
given.
(ii) If symptoms are severe adrenaline should be administered intravenously.
(iii) In future, such patients should have premedication with antihistamines
before transfusion or be given a plasma-free component e.g. washed packed
RBC for treatment of anaemia.

37. 3. Haemolytic Reactions
It is the haernolysis of donor cells if there are antibodies to them in the recipient's
plasma. There action occurs in about 0.05% of transfusions and has arnortality of 10-
50%. Itusually results from wrong identification of blood and recipient.
Natural ABO antigen-antibody incompatibility is the commonest and most important
cause and the reaction occurs instantaneously. Rh incompatibility is infrequent and the
reaction takes hours or days.Unusual causes of haemolysis are acquiredanti-Kell, anti-
Kidd and anti-Duffy antibodies.

38. The haemolysis causes shock (due to vasoactive subsiances released by
interaction between mast cells and, released anaphylatoxin derivatives) and release of
free haemoglobin, adenosinediphosphate (ADP) andplatelet factor3into theplasma.
The shock may lead to oliguria and acute tubular necrosis. Some of the haemoglobin
is converted to methaemalbumin and some is excretedby the kidneys and may in an
acid urine be converted to acid haematin and deposited in the tubules causing tubular
obstruction. ADP causes platelet aggregation which may lead to thrombocytopaenia.
Platelet factor 3 initiates disseminated intravascular coagulation which consumes
clotting factors and platelets so rendering the blood incoagulable. In a patient
undergoin gsurgery, these reactions result in uncontrollable diffuse bleeding.

39. Clinical features
They develop during or at times some hours after transfu- sionand are:
(i) Sensation of heat and pain along the vein being used for transfusion soon after
transfusion has begun; tingling of the limbs.
(ii) Headache or fullness in the head.
(iii) Rigors and fever:
(iv) Dyspnoea and constricting pain in the chest due to histamine-induced
bronchiole and vessel constriction.
(v) Pain in the loins.
(vi) Shock with hypotension. tachycardia, sweating and restlessness in severe
cases.

40. (vii) Haemoglobinuria.The urine I scoca-cola coloured.
(viii) Jaundice after some hours.
(ix) In the anaesthetized, hypotension in spite of adequate correction of blood Joss
and diffuse oozing of blood from the operation site.
(ix) Progressive oliguria to anuria due to toxic action of free haemoglobin and
inadequate renal perfusion following shock and fibrin deposition in the small
vessels.

41. Management
(i) The blood should be stopped and the remainder together with the patient's blood
taken for further groupingand cross-matching. Bedside clericalchecks should also
be done.
(ii) Further samples taken must include EDTA sample
For FBC and film comment, clotted sampleas above and post transfusion urine
sample to check for intra-vascular haernolysis. Some blood is taken for culture as
bacterial contamination may be the cause of the symptoms.

42. (iii) Laboratory confirmation.
(a) Haemoglobinaemia.
(b) Haemoglobinur ia
(c) Methaemalbuminaemia
(d) Hyperbilirubinaemia
(e) Agglutination of red cells microscopically

43. (iv) Diuresis should be established to flush the renal tubules of haemoglobin and
prevent their blockage. This is achieved by giving intravenous frusemide 40- 80 mg
or 50ml o f25% (or 100ml of 10%) mannitol intravenously in 5 minutes and
continuing the infusion with normal saline. The urine output should be about 60ml/h.
Established acute tubular necrosis is treated by peritoneal-or haemo-dialys is until
tubular function is restored.
(v) The urine is rendered alkaline by administering sodium bicarbonate intravenously
to make the haemo- globin soluble and prevent its deposition in the tubules as
insoluble acid haematin.

44. (vi) Fresh compatible blood may be necessary to correct shock. Low doses of
doparnine 4-5mg/kg/min mayalso be given to increase the cardiac output in
hypotensive patients.
(vii) If the patient is undergoing surgery and oozing of blood is severe, fresh
frozen plasma and platelets should be given to reverse the DIC

45. 4. Bacterial Contamination
About 2% of bank blood is contaminated usually atthetime of collection, and septicaemia
and/or endotoxic shock may ensue when it is transfused. It is an important cause of
transfusion morbidity and mortality. It accounts for about 16 % of transfusion-related
mortality reported in the USA. Pseudomonas species, Citrobacter freundii, E.coli and
Yersinia eruerocolitica arethemost commonly implicated organisms. These bacteria grow
rapidly when the blood is left out at room temperature. Blood should therefore be stored
in a refrigerator until it is required fortransfusion. In any case it should be used within 2h
of rernoval from the blood bank. Platelet concentrates are, however, stored at room
temperature to preserve the platelets and so may encourage bacterial proliferation.
Bacterial contamination may also occur during the setting up of the infusion or from the
drip insertion site.

46. The clinical features are:
(i) Chills, high fever anddry skin.
(ii)In severe cases hypotension from endotoxic shock and DIC.
Management
(i) The blood transfusion is stopped and an aliquot of donor blood taken for
culture and gram's stain.
(ii) The recipient's blood is also culrured.
(iii) Broad-spectrum antibiotics are administered intrave- nously.
(iv) Intravenous fluids, steroids and vasopressors such as dopamine are given to
combat shock.

47. 1. Circulatory Overload
It leads to pulmonary oedema or congestive cardiac failure. It is particularly likely to occur in
the elderly and debilitated and in patients with chronic anaemia, congestive cardiac failure,
pulmonary, hepatic or renal disease. Such patients are best given packed red cells; but if whole
blood must be given then it should be transfused slowly - I unit in 4-6h. A diuretic may be given
at the same time so that the excess fluid is excretedby the kidneys. Circulatory overload may
also occur inmassive transfusion. The symptoms and signs are
(i) Dyspnoea, orthopnoea, cough and cyanosis.
(ii) Frothy sputum.
(iii) Raisedjugular venous pressure.
(iv) Rales in both lungs.
(v) Rapid and weak pulse.

48. Treatment
(i)The transfusion is stopped and the patient proppedup.
(ii)IV frusemide removes the excess fluid.
(iii)In an emergency, phlebotomy is done to relieve the overload.
(iv)Digitalization is done to improve myocardial function.
6. Cardiac Arrest
It ismore likelytooccur inmassive transfusion (seebelow). Cold blood transfused
rapidly may cool the heart and precipitate cardiac arrhythmias.

49. 7. Air Embolism
It is uncommon with collapsible plastic bags. Rarely, it occurs duringc hanging of a
transfusion set with the needle still in the vein. It may also result from aspiration
through a leak in the giving set. As little as 10ml may prove fatal.
The symptoms and signs are:
(i) Gasping respiration, cyanosis.
(ii)Venous congestion, hypotension.
(iii)(iii) Splashing noises over the heart.
Treatment:
Oxygen is administered, the patient turned on the left side and the foot of the bed
raised. The air in the heart is then aspirated.

50. 8. Non-cardiogenic Pulmonary Oedema.
Another name for non-cardiogenic pulmonary oedema (NCPE) istransfusion-related acute lung
injury (TRALI) and the clinical picture is similar to that of adult respiratory distress syndrome
(ARDS). The cause is not well understood, but it is postulated that the pathology is due to
release of vaso-active substances like histamine, serotonin and complement fragments secondary
to a reaction between donor leucocytes and recipient anti-leucocyte antibodies or vice-versa.
The signs and symptoms include chills, cough, fever, cyanosis, hypotension and
increasing respiratory distress shortly after transfusion but without evidence of volume overload.
Chest radiographs may show pulmonary oedema but no evidence ofcardiacfailure.
Treatment includes oxygen therapy, i.v.steroids and ventilation assistance in refractory cases. Most
patients recover within 12-24h

51. B. DELAYED REACTIONS
1. Thrombophlebitis
It is more common in lower limb veins because of immobility of the legs. It
follow:
(i)Injury of the vein by the needle or cannula.
(ii)Spasm of the vein caused by cold blood.
(iii)Prolongeduseofthesamevein.
(iv) Leakageofblood aroundthevein.
(v) Sepsis.

52. Clinical features are
(i) Pain, redness, tenderness and later thickening of the vein.
(ii)Pyrexia.
Treatment:- Analgesics are administered for the pain and the affected limb rested. A
sample is taken from the tip of the needle or cannula for culture and sensitivity and
appropriate antibiotics given if there is fever.

53. 2. Delayed Haemolytic Reaction
A few days after transfusion, the patient develops mild jaundice and a drop in haemoglobin.
This delayed red cell baemolysis follows stimulation and production of antibodies which
hat the time of cross-matching were too low in concentration to be detected. It may also
result from haemolysis of old red cells especially when several units of old blood are
transfused. No treatment is indicated but the cause should be investigated. It is commoner
in patients who have received multiple transfusions.

54. 3. Post-transfusion Tbrombocytopaenic Purpura:
It is an uncommon complication and occurs about 7-14 days after transfusion. It is caused by an
anamnestic production of platclet alloantibody. It usually occurs in multiparous females. The
antibody specificity is most frequently anti-HPA-Ia. Antigen-antibody complexes become fixed
on the platelets leading to premature destruction of the recipient's platelets and
thrombocytopaenia. The patient develops petechiae and bleeding from mucous membranes.
Treatment: There is usually spontaneous recovery but prednisolone or intravenous
immunoglobulin may begiven in severe cases. Plasmapheresis may be tried in those who do not
respond to medical treatment. Transfused platelets will also be destroyed by the circulating
antibodyand replacement therapy hould be avoided as much as possible during the period of
lhrombocytopaenia.

55. 4. Transmission of Disease
1. Viral Hepatitis
Post-transfusion hepatitis is one of the most serious complications of transfusion.
The incidence has reduced ronsiderablysince the introduction of sensitive tests to
detect infected blood. The frequency of this complication varies between 0.1 and
18% and depends upon the hepatitis carrier rate in the population. Recent data
suggest that less than 0.03% of recipients of blood screened for HBsAg, anti-HBc,
anti- HCVand ALT will develop post-transfusion hepatitis.
Hepatitis C infection is now the commonest cause of post- transfusion hepatitis and
accounts for 85 %of cases and 50 %of the patients develop chronic liver disease.
Ten per cent develop cirrhosis and hepatocellular carcinoma.

56. Hepatitis B infection is less common now and the incidence has fallen from 10% ten years
ago to 0.002 % now. The infection is more severe and the incubation period is 90- 180 days
compared to 40-60 days for hepatitis C infection.
Post-transfusion hepatitis A virus infection is rare and cases are seen more often in infants
who do not have hepatitis A tlribody.
Hepatitis D infection occurs as a co-infection with hepatitis B virus or in carriers and is
usually severe, and antibody to bepatitis D virus occurs more frequently than expected in
patients with fulminant hepatitis. There is probably atl east one otherviral agent that causes some
of the clinical disease of post·transfusion hepatitis and it is designated Non-A, Non-B, Non-
Chepatitis virus.
Screening of blood for hepatitis B surface antigen(HBsAg) detects onlyone-third of infected
donor blood and the incidence of hepatitis in recipients of HbsAg negative blood is reduced by
about 30 %.

57. The clinical features of viral hepatitis are
(i) Malaise., Fever
(ii) Anorexia, nausea or vomiting
(iii) Jaundice
(iv) Tender enlarged liver.
(v) Deepening in colour of urine.

58. Laboratory Findings
(i) Elevated transaminascs.
(ii) Elevated serum bilirubin: Direct hyperbilirubinaemia.
(iii) Elevated serum alkaline phosphatase.
(iv) The serological features of acute hepatitis B virus infection are positive hepatitis B
surface and e anti- gens plus a positive hepatitis B core IgM antibody. For hepatiris C
virus infection, there is a positive lgM antibody. For hepatitis D virus infection, the
features are those of hepatitis Bplus positive hepatitis Dvirus antibody.
Other viruses that may be transmitted are cytomegalovirus, human T lymphorrophic virus,
Parvovirus 819 and Epstein Barr virus.

59. Management
(i)Bed rest
(ii) Alfa-interferon cures 25-50% of patients
(iii) Glucose drinks, low fat diet.
Vaccines for hepatitis A and hepatitis B arc available for patients and
individuals at risk of hepatitis infection.

60. II. Malaria
As the malaria parasite may persist for years in a potential donor and survives storage, it is
readily transmitted. It is therefore suggested that in endemic areas recipients should be
monitored for malaria and treated as needed.
The clinical features are
(i) Rigors and fever.
(ii) Headache, myalgia and malaise.
(iii) Sweating
Malaria parasites are usually found in the blood film.
Treatment: Combination therapy as prevails at the tlme currently, Artesunate and
amodiaquine are given.

61. III. Syphilis
Syphilis can only be transmitted in blood which is used before 48h as the spirochaete
dies within 48h of storage. Syphilis transmission bytransfusion is not prevented by
serological testing of donors because seroconversion occurs well after the phase of
spirochetemia. The test is now required as an indicator of potentially high-risk
behaviour.
IV. Cytomegalovirus Infection
The features resemble those of viral hepatitis and it is likely that some recipients who
develop jaundice aftert ransfusion are in fact victims of this disease. It may be fatal in
premature infantsand in recipients of organ and marrowt ransplants. This may be
prevented by giving such recipients CMV-negative or leucocyte-poorbtood.

62. V. Human Immunodeficiency Virus (HIV) Infection
HIV (See also Ch. 2) is the cause of AIDS and is an important contaminant of blood and
blood products. The prevalence among blood donors varies from place to place and
ranges becween 0.001% and18%. The risk of infection is higher in pooled products like
Factor VIII concentrate(I in 200) and lowest in single donations like packed red blood
cells (1 in 100,000). Screening of donor blood has reduced the incidence oftransfusion-
associated infection by 95%. This implies that about 5% of donors who test negative by
current screening methods are infective.
The incubation period is 6 months to 6 years or more with an average of 28 months.
About 90% of recipients of HIV- infected blood be come seropositive and AIDS develops
in about half of them within 7 years.

63. VI. Variant Creuzfeldt-Jacob Disease (vCJD)
vCJD is a rare but fatal neurodegenerative disease acquired from bovine spongiform
encephalopathy (BSE or mad cow- disease) infected material. The disease is
characterized by the accumulation of a modified host protein (prion protein) in the
brain. The diagnostic histological features are neuronal loss, astrocytosis and
spongiform change. The development of antibodies to prion protein has resulted in the
development of more specific daignostic tests like imrnunocyto-chemistry and Western
blotting.
vCJD differs from other forms of CJD by virtue of the fact tbat the infectious agent
is also found in lymphoid tissue and clinical diagnosis can be made through the MRI
findings (the pulvinar sign) and the demonstation of prion protein in tonsillar biopsy
material.

64. The incubation period is unknown but appears to be about 6.5years. No rapid reliable
and non-invasive diagnostict est for carrier status is currently available. The first two cases
of transfusion-associated vCJD were reported in 2004 and since then the following
measures have been approved byWHO for reducing the risk of transmission of the disease
through blood transfusion:
a)Permanent deferral of all blood donors who have received a transfusion in the UK
and France since January 1980.
b)Withdrawal and recall of any blood components, plasma derivatives and tissues
obtained from any individual who later develops vCJD.
c)Leucocytic depletion of all blood components.
d)Deferral of all donors who have had dura-matertrans- plant, human-derived
pituitary hormone therapy or a family history of vCJD.

65. VII. Other diseases
Trypanosomiasis, toxoplasmosis, infectious mononucleosis and brucellosis may
also be transamitted.
5. lmmunosuppression: Transfusion has been known to affect the immune system
since the 1970's when it was observed that previously transfused patients had
significantly improved renal allograft survival. Further studies linked post·
operative bacterial infections and a higher recurrence rate of resected colorectal
cancer with blood component transfusion.

66. These observations are based on meta-analysis and no specific mechanism or
mechanisms have been proven so far. Reticulo-endothelial blockage has been
postulated as the cause of the immunosuppression but no supportive cause-and-
effect relationship has been identified. Tt is important to note, however, that blood
component transfusion may result in immonosuppression in the recipient.
There is some evidence that leucocyte-depleted blood transfusion does not
have the same effect on immunosuppres- sion as blood containing leucocytes.

67. 6. Transfusion-Associated Graft-versus-Host Disease
This is a rare but highly fatal complication of blood transfusion. The "at-risk" groups
includepatiemswithcongeni!al immunodeficiency syndrome, stem cell transplant
recipients, newborns receiving exchange transfusions, fetuses receiving intra-uterine
transfusion and patients receiving blood from close relatives.
The disease is caused by a proliferation of T-lyrnphocytes from the donor
responding immunologically to histccompaubiliry antigens in the recipient. Clinical
symptoms and signs appear in about 3 to 30 days after transfusion and include fever,
severe diarrhoea, erythematous desqcamating skin rash an delevated liver enzymes.
The commonest causes of death are infections and bleeding.
TA-GVHD is prevented by irradiation of blood before transfusion. The usual dose
is 25-35Gy.

68. Problems Associated with Massive Transfusion
Massive blood transfusion is defined as the replacementof one or more of the
patient's blood volume within 24h or about 5L in an adult. If the bloodt ransfused is
stored blood, then the following complications may ensue:
1. Circulatory Overload: Rapid and excessive transfu- sion may overload the
circulation and result in pulmonary oedema and/or congestive cardiac failure. This is
more com- mon in elderly or debilitated patients.

69. 2. Cardiac Arrhythmias and Arrest: These are caused either singly or in combination by
the following:
(i) Cold blood: It causes hypothermia which results in cardiac depression and
arrhythmias. Shivering may occur, increasing the oxygen demand. The blood
should therefore be warmed before it is used.
(ii) Hyperkalaemia: As stored blood has a high potas- sium concentration (20-
30mmol/L)(because of the efflux of potassium from the red cells to the plasma
following the breakdown of the Na-K pump due to anaerobic glycolysis), large
quantities infused rapidly may raise the potassium conceruration of the recipient’s
plasma and precipitate cardiac arrhythmia.

70. (iii) Hypocalcaemia: The citrate ion of the CPDA-1 anticoagulant of banked blood
combineswithionized calciumoftherecipient's plasmacausing hypocalcae- mia. This depresses
myocardial function seen clini- cally as low arterial blood pressure and pulse pres- sure. It may
potentiate the action of hyperkalaemia and precipitate cardiac arrest. Tetany may occur. To
prevent this, patients receiving massive transfusion should be given I0ml of I0 % solution of
calcium gluconate in a vein other than the one being used for the transfusion for every litre of
blood transfused .
(Iv) Acidosis: Banked blood is acidic with a pH of 6.6, pCO of 150-210mm Hg and basedeficit of
9-15mmol/ Lat J4 days. lt results from excess citrate ions in the CPDA-1solution and production
of lactic acid by the red cells. It may cause myocardial relaxation, decreased contractility,
increased irritability and predispose toventricular fibrillation.Thepatient's acid- base and
electrolytes should therefore be checked frequently.

71. 3. Respiratory Complications
They may follow the pulmonary sequestration of micro- aggregates in the stored
blood. These micro-aggregates which are made up of cellular membranes,
platelets, leucocytes, fibrinstr ands and protein precipitate, are I0-160 microns in
size and number about 140,000/ml. Millions of them will enter the venous blood
as the pore size of the standard drip filter is 170.23-0microns.
By using microfilters, however, the micro-aggregates are removed

72. 4. Bleeding Diathesis: There may be excessive uncontrolable bleeding during surgery due to:-
(i) Thrombocyropaenia:-Banked blood contains nofuncioning platelets and dilutes the recipient's
platelets.
(ii) Deficiency of clotting factors V and Vlll in banked blood.
(iii) Hypocalcaemia for reasons stated above.
Patients receiving massive transfusion should, therefore, should be given platelet concentrate
and fresh frozenplasma (l unit for 5units of banked blood if clotting factors are not available) to
provide functioning platelets and clotting factors and 10% calcium gluconate (l0ml for every
litre of blood) to prevent hypocalcaemia. At best, the coagulation status and platelet oount
should be checked and specific deficits corrected.
For example, platelets should be given if the platelet count ~<50x109/L, fresh frozen plasma
if the prothrombin time is >16sec, and cryoprecipitate if the fibrinogen level is < I 100mg/ dl.

73. 5. Reduced Oxygen Delivery: The 2,3- diphosphoglycerate concentration of red cells
in stored blood is reduced. Consequently, release of oxygen to the tissues is reduced
if large amounts of such blood is given. A hypoxic patient is not likely to benefit from
such blood and so should be given fresh blood.

74. AUTOLOGOUS TRANSFUSION
It is the collection and subsequent re-infusion of the patient's own blood. It is being
increasingly practised because it prevents transmission of diseases such as HIV and
viral hepatitis and avoids immunological complications of allege- neic transfusion
such as alloimmunization and transfusion reactions.It reduces the demand on blood
banks for donor blood. It is very useful in centres with limited or absent blood
transfusion service especially in emergencies.

75. The principal methods are the following:
1. Preoperative Autologous Blood Donation (PABD)
It is an effective method for patients for elective surgery. The patient donates
preoperatively 1-5 units of his/her blood which can be used to replace blood loss if
necessary. The patient's haemoglobin should be over 10g/dl and the PCV over 30%.
Patients with bacteraemia, serious cardiac disease and sickle cell disease should be
excluded.
Donations should be 3-7 days apart and the last one should not be within 72h of
surgery. The patient is given iron supplement e.g. ferrous sulphate to elevate his
haemoglobin level.

76. Recombinant human erythropoietin can also begiven. It increases the volume of
autologous blood that can be collected as it enhances production of redcells.
On the morning of surgery, ABO and Rh groupings are done and if crossover of
unused autologous blood is contemplated, then tests for transfusion-ransmined
diseases are also mandatory.

77. 2. Acute Isovolaemic Haemodilution (AIVH)
In AIVH,1-4units of the patient's own blood are removed immediately prior to the commencement
of surgery and replaced simultaneously with a crystalloid (3.0ml for every 1.0ml of blood collected)
and/or colloid (1.0ml fo revery 1.0ml of blood collected) to maintain the circulating blood volume.
The autologous blood collected is re-infused during or after the operation. Only standard plastic
blood packs containing CPDA-1and transfusion sets with filter are required. The patient’s initial
haemoglobin and PCV shouldbe > I2g/dl and 36% respectively and must not fall below 9 g/dl and
27% respectively after haemodilution. Blood is collected from one venous line while simultaneous
replacement with crystalloid or colloid is carried out viaa second venous line. The pulse, blood
pressure and urine output should be monitored during the collection. The autologous blood is re-
infused if excessive bleeding occurs or preferably after major bleeding has been controlled.

78. 3. Intra-operative Blood Salvage
Shed blood from a wound or body cavity during surgery is collected and
subsequently re-infused into the same patient. It is useful in ruptured ectopic
pregnancy, ruptured spleen, penetrating injuries, haemothorax, cardiovascular surgery
and some orthopaedic surgeries.
The shed blood in a body cavity is collected with a ladle or gallipot into a kidney dish
or large bowl containing an anticoagulant. The blood is filtered into a bottle through
4-6 layers of sterile gauze placed in a funnel. The bottle is then sealed and the blood
re-infused.

79. A special machine is available which aspirates the blood, adds heparin, filters and washes it and
uses a roller pump to re-transfuse it. With the Haemonetic Cell Saver, only concen- trated red
cells are retransfused. The main complication is bleeding because washing removes clotting
proteins.
A re-usable suction collection system is also available. Shed blood undergoes varying
degrees of coagulation, fibrinolysis and haemolysis and infusion of unwashed blood may trigger
DIC.
If collected under asceptic conditions with a saline-wash device, blood collected by salvage
has a shelf-life of 6h at room temperature and 24h if stored at 4°C. It should beproperly labelled
with date, time of collection and expiration and the inscription "For autologous use only".
Inblood salvage, haemolyzed or infectedblood should not be used. This procedure is contra-
indicated in patients undergoing tumour resection because of concern about re- infusing rumour
cells.

80. 4. Postoperative Blood Salvage
If postoperative blood loss is likely to cause haernodynamic instability and require
homologous blood transfusion, then blood satvage may be considered. Blood is satvaged
from body cavities and joint spaces and reinfused. This method is most useful incardiac
surgery, penetrating chest injuries and some orthopaedicprocedures.The precautions
indicated for Intra- operative Blood Salvage also apply for this type of blood salvage.

81. In the absence of blood, substitutes are used to replace lost circulating blood volume in
hypovolaernic patients.
The following criteria for a replacement fluid have been laid down by the American
National Research Council:
1. The colloidal osmotic pressure should be equivalent to that of normal plasma.
2. The half-life in circulation should be at least 6 and preferably 12h.
3. It should be non-toxic and should not be stored in the body.
4. ll should be metabolized or excreted so that there is no interference with organ
function, even after re- peated administration.
5. It should be non-pyrogenic, non-allergenicand non- antigenic.

82. 6. It should be oflow viscosity.
7. It should not interfere with haemostasis or coagulation.
8. It should not cause agglutination of or damage to red or white cells.
9. It shouldnot interferewith blood grouping.
10. Itshouldnotinterferewith immunefunction.
11. It shouldnot interfere with haemopoiesis.
12. It should not interfere with renal function or cardiac output.
13. It should not create metabolicacidosis.

83. Plasma substitutes include plasma expanders, electrolyte solutions and hypertonic
solutions.
1. .Plasma expanders are:
a. Stable plasma protein solution
b. Albumin
c. Dextran
d, Synthetic gelatin colloids (Haernaccel, Gelofusine) e . Hydroxyethyl starch
preparations (Hetastarch, Penrastarch)

84. a. Stable Plasma Protein Solution
It is a suitable plasma replacement fluid as it contains plasma proteins mainly albumin
(83%) and globulins (17%), and so has the same colloidal osmotic pressure as normal
plasma. It is heat-treated and free of viral infections. It is, however, expensive but very
useful in an emergency as a safe plasmaexpander.
b. Albumin
Its colloid osmotic pressure is the same as plasma and so is a suitable replacement fluid.
It, however, replaces only albumin and only for a short period of about 24hrs. It is also
expensive and contains no immunoglobulins and coagulation factors.

85. c. Dextran
Dextrans are polysaccharides with sugar as the base. They are cheap and readily available
but their use generally have been limited because of side effects especially aller gic reactions
and haemostatic disorders.Theyalso interfere with blood grouping when used.
Dextran 70 (Macrodex)
Usually supplied as 6% solution with or without saline, it has a M.W. of 70,000, a higher colloidal
osmotic pressure than has normal plasma, and so is retained in the vascular compartment;it thus
supports the blood volume. It is excreted in 24-48h. As the glomerular filtrate is of high viscosity, it
passes through the tubules slowly and may cause renal damage especially in the dehydrated. By
coating the platelets and reducing their adhesiveness, it tends to interfere with coagulation and cause
bleeding. It also interferes with the action of factor VIII. It should therefore be avoided in patients
with wounds.

86. Because of its high colloidal osmotic pressure, it withdraws fluid from the extravascular
into the intravascular space thereby increasing dehydration in the dehydrated; a litre is
approximately equivalent to 1.3L of plasma. Over expansion of the blood volume may
therefore occur, and if excessive amounts are given pulmonary oedema results. Not more
than a litre should therefore be given in 24h and it should be used with caution in patients
with cardiac, hepatic or renal failure. As dexrran inhibits platelet aggregation and causes a
transient increase in bleeding time, it is contra-indicated in patients with pre-existing
disorders of haemostasis.

87. It induces rouleaux formation of red cells and so may interfere with blood grouping
and cross-matching. Blood for grouping must, therefore, be taken before dextran
infusion. Anaphylactoid reactions may occur in 0.07 % of recipients when
hypotension may result.
Forall these reasons, dextran 70 is not a very satisfactory fiuidforreplacing blood
volume. Dextran 110 is also available. Dextran 40:- With a M.W. of 40,000 i.e. less
than that of plasma, it is more rapidly excreted i.e. within 24h. It lowers
bloodviscosity and may interfere with the action of factor Vlll and platelet
aggregation and because of these it is used to prevent post-operative deep vein
thrombosis in high risk patents. It is available as l 0% solution in either isotonic
saline or 5% dextrose.

88. d. Haemaccel (Gelatin): It is a colloidal infusion olution containing degraded gelatine
polypeptides. It has a M.W.of 35,000 and a half-life of 4-6h. It may cause anaphylac-
ioid reaction in 0-1 % of patients. It does not interfere with clotting or blood grouping
and renal function is unimpaired. It is therefore a satisfactory volume replacement
fluid. Dosage, oowever, should not exceed 2L in the first 24h and it is contra-
indicated in patients with established renal failure.
Gelofusine is modified gelatin 4 %, MW 30, 000 in normal saline. It has no effect on
clotting or crossmatching. It promotes an osmotic diuresis.

89. e. Hydroxyethyl starch preparations: They have a mlf·lifeof about 6-8h and can restore
volume for up to 36h. The MWis200,000-450,000. Only l-l.5L is given daily. Volume
expansion is equal to the volume infused. The incidence of antigenic reaction is low.
Sequestration into the RES may oocurbutno adverse reaction has been reported. It is a
valuable volume expander but itmay interfere with coagulation.
2. Electrolyte Solutions (Crystalloids): They are readily available and cheap. The
colloid osmotic pressure is very low and so they rapidly diffuse through all the
compart- mentswhich is often beneficial. But only about 30% remains inthe
imravascular compartment, e.g. Normal Saline and Ringers Lactate.

90. 3. Hypertonic solutions
Hypertonic solutions -3%NaCl, 7.5%NaCl/Dextran 70 and hypenonic Ringer's lactate
- have been used to resuscitate patients with haemorrhagic shock and burns. They are
retained inthe intravascular compartment and the initial volume is iocreased by egress
of intracellular fluid. They, therefore, quickly improve cardiac and haemodynamic
functions and urinary output; smaller volumes than ordinary crystalloids are required.
However, they may cause cellular dehydration, brain shrinkage, serum hyper-
osmolality and hypernatraemia (which may lead tof luid overload and cerebral
oedema), hypokalaemia (from diuresis) and even worsen uncontrolled bleeding.
On tbe whole, there is no long-term advantage of hypertonic olutions over Ringer's
lactate.

91. Red Cell Substitutes
Diaspirin cross-linked haemoglobin solution has similar oxygen transport and exchange
properties as whole blood. It is aseffective as whole blood inrestoring haemodynamics after
haemorrhagic shock. The perfluorocarbons are also oxygen- carrying solutions. They
dissolve oxygen which isreleased to tissues by diffusion; 100% inspired oxygen is required
during their use. These substitutes are not yet ready for use in clinical practiced despite
ongoing research.
Other substitutes under investigation, include stroma-free haemoglobin, encapsulated
haemoglobin and recombinant DNA derived haemoglobin. Stroma-free Hb is readily
available and stable on storage, but has a high oxygen affinity, short half-life and is
nephrotoxic. Chemical modifications may overcome these disadvantages.