Blood preservatives

1. Dr. ZIKRULLAH

2.  The process by which blood or its
components are kept viable outside the
body (i.e., kept away from decay by
means of a chemical agent, cooling, or a
fluid substitute that mimics the natural
state within the body) is called blood
preservation.
 Goal of blood preservation - to provide
viable & functional blood components for
patients requiring blood transfusion.

3. PHYSICAL
 Disc changes
 Changes in
deformability due to
loss in membrane
lipids
 Increased osmotic
fragility
 Loss of heat labile
coagulation factors
 Apoptotic changes
BIOCHEMICAL
 Decrease in ATP
levels
 Build up of lactic acid
 Decrease in pH
 Decrease in 2,3 DPG
levels leading to shift
of oxygen
dissociation curve
 Clotting of blood

4.  When blood is stored at 2-6 °C, glycolysis is
reduced but does not stop. Glycolysis results
in the production of lactate, with subsequent
decrease in pH , which alters red cells
viability.
 Preservative solutions provide buffering
capability to minimize pH changes and
optimize the storage period.

5. A fall in pH in the stored blood results in –
 decrease in red cell 2,3-DPG level by
inhibiting RBC glycolysis which results in
increase in hemoglobin-oxygen affinity.
 DPG-depleted red cells have impaired
capacity to deliver oxygen to the tissues.

6.  However , after transfusion the red cells
continue to synthesize 2,3-DPG and levels
return to expected normal values within 24
hours.
 Rate of restoration of 2,3-BPG is affected by
acid-base status of recipient
phosphorous metabolism
degree of metabolism

7. Decrease in ATP results in
 Leak of Na and K ion from the cell membrane
 Increased osmotic fragility
 Increased lysis of RBC
 Increased plasma Hb levels

8.  The first anticoagulant preservative was introduced
by Rous and Turner in 1916,consisted of a citrate-
glucose solution. Rous Turner's solution was used
for storage of human blood during the First World
War.
 During the Second World War acidified citrate
dextrose (ACD) solution was introduced .

9.  In 1957 Gibson developed an improved
preservative of citrate-phosphate-dextrose (CPD),
which was less acidic and maintained 2,3-BPG level
better than in ACD solution.
 In 1978 citrate-phosphate-dextrose with adenine
(CPDA-1) preservative was developed. The addition
of adenine improved the synthesis of adenosine
triphosphate (ATP) in the stored blood, which
prolonged the storage of blood/red cells at 2-4 °C
to 35 days

10.  ACD(acidified citrate, dextrose)
 CPD(citrate , phosphate , dextrose)
 CPDA(citrate, phosphate , dextrose , adenine)

11. Citrate
Calcium chelator , prevents coagulation and
retards glycolysis .
 Citrate toxicity- hypocalcaemia and
hypomagnesaemia which can result in myocardial
depression or coagulopathy .
 Considered to be a cause of cardiac arrythmia in
massive transfusion.
 Management- Slowing or temporarily stopping the
transfusion allows citrate to be metabolised.
Replacement therapy may be required for
symptomatic hypocalcaemia or hypomagnesaemia.

12.  Adenine- substrate for ATP synthesis, extends the
shelf life of red cells to 42 days as RBC has ATP
dependant cytoskeleton.
 Sodium di phosphate –act as buffer and thus
prevents fall in pH .
 Dextrose - improves red cell viability by providing
energy for ATP synthesis decreases rate of
hydrolysis of phosphorus.
 Citric acid- prevents glucose caramalization during
autoclaving provides optimal pH with citrate for
red cells.

13. Acid citrate dextrose (ACD):
Composition –
 Tri-sodium citrate- 22 gm
 Citric acid (monohydrate) -8.0gm
 Dextrose (monohydrate)-24.6 gm
 Distilled water upto1litre
For each 100 ml of blood, 15 ml of the ACD
solution is needed

14. Advantages of ACD-
 Preserves ATP level
 prevents haemolysis
 maintains pH
 Shelf life of whole blood / red cells in ACD =
21 days
 > 70% transfused cells viable after 24 hours
However level of 2,3 BPG lost early within first
week

15. Citrate phosphate dextrose (CPD)
CPD is a modified ACD solution that is slightly less
acidic and therefore improves the preservation of
2,3-BPG.
Composition-
Tri-sodium citrate- 26.30 gm
Citric acid- 3.27gm
Dextrose- 25.50gm
Sodium phosphate-2.22gm
Distilled water upto1litre
For each 100 ml of blood 14 ml of CPD is added.

16. Avantages of CPD Solution –
 Better maintenance of 2,3 BPG
 decreases acidosis
 improves ATP synthesis
 Shelf-life of whole blood in CPD = 21 days

17. Citrate Phosphate Dextrose Adenine (CPDA):
Adenine - helps maintain high ATP levels
ATP is associated with red cell viability .Loss of ATP
causes increase in cellular rigidity & decrease in red cell
membrane integrity & deformability. A decrease in ATP
allows the leak of Na & K through red cell membrane.
Shelf-life = 35 days

18. Variable 0 day Whole blood Packed cell
pH 7.55 6.73 6.71
Plasma
haemoglobin(mg/
dl)
0.50 46 246
Plasma
potassium(mEq/l)
4.20 17.20 76
Plasma
sodium(mEq/l)
169.00 153 122
Blood
dextrose(mg/dl)
440.00 282 84
2,3 DPG 13.20 1 1
Percent survival - 79 71

19.  Inhibits coagulation by inactivating factor Xa
, IXa,XIa,plasmin
 potentiates action of antithrombinIII
 Dose for anticoagulation-0.5 to 2.0IU/ml
 It has no preservative property and its
anticoagulant effects are neutralized by
plasma
 To be transfused in 24 hrs

20.  Sodium salts act as chelating agents and
prevent coagulation by binding with Ca
 Toxic and damages platelets
 Not used in blood transfusion
 Used for preserving blood samples only

21. Traditional preservatives were put into use when
whole blood was the major product. With the
advent of component therapy, use of red cells
increased , and so the need of different
preservative methods . These include-
1. Optimal additive solutions
2. Rejuvenation solutions
3. Red cell freezing

22. Normally 40% of adenine and glucose present in
the whole blood, was removed in preparation of
packed RBC and thus there was decrease in its
viability particularly in last 2 weeks of storage.
 RBC became more viscous and difficult to infuse in
emergency situation
 However preparation of concentrates of
haematocrit less than 80% by allowing adequate
plasma to remain, lead to lower plasma yields
affecting FFP and Cryoprecipitate production.

23.  Thus use of additive solutions for preparation
of packed RBC allowed recovery of maximum
amount of plasma for preparation of FFP and
cryoprecipitate.

24.  Different types of additive systems are now in
use -
(1) Adsol - ( AS-1 )
(2) Nutricel - (AS-3)
(3) Optisol - (AS-5)
 OAS are added to the red cells after
separating them from plasma.

25. AS-1 AS-3 AS-5
Sodium citrate - 588 mg -
Monobasic sodium phosphate
- 276 mg -
Citric acid - 42 mg -
Dextrose 2.20 g l.l0 g 900 mg
Adenine 27 mg 30 mg 30 mg
Mannitol 750 mg 525 mg
Sodium chloride 900 mg 410 mg 877 mg
Vol 100 ml 100 ml 100 ml
Primary bag anticoagulant CPD CPD2 CPD
COMPOSITION OF ADDITIVE SOLUTIONS

26. The advantages of using optimal additive solution
to red cells are -
 Provide the red cells with adequate nutrients.
 Better storage condition for red cell preparation
and lowering of viscosity for ease of transfusion.
 Increased yield of plasma for plasma fractionation.
 Removal of unwanted buffy coat
 Avoid unnecessary transfusion of plasma
 Mannitol acts as membrane stabilizer and reduces
hemolysis to acceptable levels

27.  Additive system increase the level of ATP and
red cells, extending the shelf-life of the red
cells to 42 days.
More than 80% red cells survive in circulation
24 hours after transfusion of blood stored for
42 days.

28. Disadvantage of additive solutions
Additive solutions do not maintain 2,3BPG
throughout the storage time .Therefore , blood
stored in additive solutions is not given routinely
to newborn infants.

29.  PURPOSE : To increase levels of 2,3 BPG and ATP in
stored red cells. Added at any time between 3 days
post collection and three days after expiration of red
cells.
 Consists of – phosphate
inosine
glucose
pyruvate
adenine
Rejuvenation process is expensive and consumes time
and is rarely used.
(in autologous donations/rare blood groups)

30.  Frozen red cells can be stored for 10 yrs but
freezing damages red cells due to the
intracellular ice formation & hypertonicity . To
counter this glycerol is added.
 Glycerol prevent freezing injury in human red
cells & red cells mixed with glycerol could be
frozen without damage.

31.  Two concentrations of glycerol are used-
 High glycerol(40% w/v)
 Low glycerol(20% w/v)
 Most blood banks use high glycerol technique
 Generally cells are glycerolized and frozen
within 6days of collection of blood in CPDA
but RBCs in additive solution can be frozen
upto 42days.

32.  RBCs frozen at high glycerol can be stored for
10 year.
 Those frozen at low glycerol can be stored for
3 year.
 Frozen RBC need to be deglycerolized before
transfusion.
 Deglycerolized for 24 hr.

33.  High cost
 Short post thawing shelf life(24 hrs)
 Increased red cell loss in processing
 Increased processing time in emergency

34. Preservation of viable & functional platelets depends on –
 Temperature – should be stored at 22 – 24 C with
continuous gentle agitation in platelet incubator &
agitator.
 pH – should be above 6.
 Plastic bag – maintenance of pH & function of platelets
depends on permeability of storage bag to oxygen & CO2.
 50 to 60 ml of plasma is needed for storage as it provides
bicarbonate buffers
inhibitors of coagulation activation
glucose as metabolic substrate

35. Platelets should be prepared within eight hours
of phlebotomy and stored at 20-24 C with
continuous agitation, to prevent aggregation
which can result in loss of viability.
 Platelets are stored in large flat bags with a high
surface-to-volume ratio ,on agitators to facilitate
oxygen diffusion. If there is no agitation for more
than 24 hours, the bag contents become hypoxic
and the metabolism shifts to anaerobic glycolysis
so that the contents become acidotic and the
platelets lose their function.

36.  Synthetic mediums to replace significant portion of plasma
volume
PRIMARY INGREDIENTS
1.Citrate-prevents activation of anticoagulation
2.Acetate-serves as substrate for activation of anticoagulation
3.Sodium chloride-isotonicity and osmotic strength
4.Phosphate-stimulation of glycolysis and maintenance of
physiologic pH
5.magnesium/potassium-decreased platelet activation , improves
morphology score , decreased lactate production

37.  Reduction of allergic reactions and febrile
transfusion reactions
 Facilitate ABO incompatible platelet
transfusion
 Plasma not used can be used for other uses
 Support 7days of platelet storage
 Improved efficacy of platelet collection

38.  Shelf life of FFP is 12 months at – 18 C or lower.
 After thawing, FFP can be stored at 2 – 6 C for 12
hrs before transfusion.
 If FFP can not be used within 1 yr or thawed
plasma is not used within 12 hrs it is re
designated as single donor plasma which can be
stored further for 4 yrs at – 18 C or lower.

39.  Cryoprecipitate is prepared from plasma. It
contains fibrinogen ,von Willebrand factor
and factor VIII.
 Cryoprecipitate can be stored for 12 months
at – 18 C or lower.
 Thawed cryoprecipate can be stored for 6 hrs
at 2 – 6 C & pooled cryoprecipitate kept at 2 –
6 C should be used within 4 hrs.

40.  One of the major factors important in
viability of transfused red cells are plastic
bags used for storage
 They should be sufficiently susceptible to co2
so as to maintain higher pH during storage
 Currently blood is stored in bags made of
PVC and DHEP

41. THANK YOU