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Use of blood components in clinical practice - Part 2
1. USE OF BLOOD COMPONENTS IN CLINICAL
PRACTICE – Part 2
By
Dr.Varughese George
2. Platelets :
• Non-nucleated, smooth disc-shaped
cellular fragments that are produced by
‘budding off’ from megakaryocytes in the
bone marrow.
• Measure 2-4 µms in diameter.
• Have a circulatory lifespan of 8-14 days.
• The normal adult count is 150-400 x 10⁹.
• 10-20% of the total platelet population
lies within the spleen.
• Required for primary haemostasis.
• Releases vasoconstrictors (e.g
thromboxane A2 & serotonin) are
involved in the initiation of coagulation
and are essential for retraction of the final
clot.
3. Collection of Platelets
• Platelets are collected in two ways :
Pooled platelets
This is a two-step procedure
1 unit of platelet is produced from a unit of whole blood.
4-6 of these units (from different donors) are pooled together in a single pack to
be given to a thrombocytopenic patient.
Apheresis platelets
These have the advantage of being collected from a single donor to reduce the
risk of disease transmission.
As blood cycles through apheresis machine, platelets are removed and all other
blood constituents are returned to the donor.
The amount of platelets collected with this procedure represents the equivalent
of 4-6 units of random donor platelets.
4. Storage of Platelets
• Platelets last for 3-5 days if stored on an agitator at 22 ⁰C at pH of
6.2-7.8.
• Each platelet bag has a volume of 250-350 ml.
• Should be inspected prior to infusion.
• Should be rejected/referred for further opinion if there is any
unexpected appearance such as discolouration.
• Not cross-matched with the recipient, but wherever possible ABO
specific platelets should be used.
5. Storage of Platelets
• Risk of transmission of bacterial infections is higher with platelet
transfusions than red cells if stored for 3 days or more.
• Bacterial contamination may occur at the time of collection.
• The storage bags are made up of specific plastic, which allows gas
exchange (for O2 & CO2 ) to occur across its walls at 22 ⁰C preserves
platelet function but promotes bacterial growth.
• The longer the platelets are kept prior to transfusion, the higher the risk of
bacteremia.
6. Recommendations for platelet
transfusion
• Appropriate use of platelet transfusion can reduce the volume of red cells
transfused.
• When a platelet transfusion is considered, the quality of endogenous platelets
should be taken into account as well as recipient’s platelet count
• Platelet transfusion may be indicated despite an apparantly normal platelet
count if there’s known or suspected platelet dysfunction.
• In stable patients, platelet count > 10 x 10⁹/L in absence of bleeding is satisfactory.
• In surgical if the platelet count > 100 x 10⁹/L or obstretic patients with normal
platelet count, platelet transfusion is rarely indicated and usually indicated if
count < 50 x 10⁹/L in the presence of bleeding.
• Invasive intervention in a patient with platelet count < 5 x 10⁹/L .
• Decision on platelet transfusion in patients with platelet counts between 50 & 100 x
10⁹/L should be based on platelet dysfunction, expected/ongoing bleeding or risk of
bleeding.
• Prophylactic platelet transfusion is rarely indicated and ineffective in ITP/TTP.
• Each adult therapeutic dose of platelets can raise the count by approx. 20 x 10⁹/L .
7. PLATELET RICH PLASMA (PRP) & PLATELET RICH CONCENTRATE (PC)
PLATELET RICH PLASMA (PRP)
&
PLATELET RICH CONCENTRATE (PC):
• Can be prepared from
-Random donor platelet (from 450ml whole
blood) 4 – 5 PRP units conc. in AS/ SAG-M
(additive solution)
-Single donor platelets prepared by apheresis
in cell separator.
-Random Donor Platelets – 450ml whole
blood at RT (20-22⁰C) within
6-8hrs of collection.
8. • Thrombocytopenia:
-Due to decreased platelet production – in this
endogenous / exogenous platelet survival is normal
and platelet supportive therapy is useful:
-Leukaemia
-Chemotherapy
-BM transplantation
-Marrow infiltrative diseases
-Drug induced suppression
-Radiation induced hypoplasia
9. Due to increased platelet destruction – endogenous/
exogenous platelet survival is shortened and benefit
of platelet transfusion low:
Immune platelet destruction/ loss:
-Idiopathic thrombocytopenic purpura (ITP)
-Autoimmune thrombocytopenia
-Drug induced thrombocytopenia
(quinidine/ heparin)
-Gram negative septicaemia.
11. Indications of platelet transfusion:
-Platelet count < 5000/ul due to any conditions.
-Platelet count – 5000 – 10000/ul – if increased
risk of bleeding due to hematological
malignancies, sepsis, BM aplasia/ transplant.
-Platelet count – 10000 – 20000 /ul if bleeding
present mucus membranes, surgical incisions,
venipuncture site, scattered patechiae/ echymosis.
-Chemotherapy - platelet count < 20,000/ul
-DIC - if platelet count < 50,000/ul
-Massive transfusion - if platelet count < 50,000/ul
-In major surgery - if platelet count - <70,000/ul
12. • DOSAGES:
One unit random donor platelets 5000 – 10,000/ul
One unit apheresis donor 30,000 – 60,000/ul
Monitoring - Platelet count, BT, PT, Aptt, Fibrinogen.
-ABO incompatability – acceptable.
-Rh negative females given compatible platelets
otherwise Rh Ig 20ug for each unit of platelets to be
given.
13. • Contraindications:
-Thrombotic thrombocytopenic purpura (TTP)
-Heparin induced thrombocytopenia
-Idiopathic thrombocytopenic purpura unless
life threatening hemorrhage.
-No prophylactic use <50,000/ul in surgery.
14. GRANULOCYTES:
• Indicated for life-threatening infections in neutropenic cancer patients
who are unresponsive to antibiotics.
• Prepared by separating white cells from blood donated by volunteers
whose leucocyte count has been increased by pre treatment with
corticosteroids, or with chronic granulocyte leukemia.
• Blood donations must be cross-matched as they contain large numbers of
RBCs.
• Should also be irradiated to remove lymphocytes.
• Collected either by apheresis or derived from whole blood and can be
stored for 24 hrs at 20-24 °C.
15. GRANULOCYTES:
Indications:
Septicaemia not responding to antibiotics
Infections in patients of chemo / radiotherapy
Gram –ve infections with neutrophil counts < 500/cumm
Temporary bone marrow depression in 1-2 weeks
Products:
Buffy coat –from 450ml blood 0.60x10⁹ granulocytes,
other leucocytes, RBC, platelets,
15-20ml plasma.
Apheresis – Granulocytes (1x 1010), other
leucocytes , RBC, Plasma 200 ml.
16. • Doses and administration:
1 unit prepared by apheresis (equivalent to 18-20
units of buffy coat ) daily.
• Contraindications:
Infections responsive to antibiotics.
17. FRESH FROZEN PLASMA
• Mainly used to provide replacement coagulation factors in cases of
excessive bleeding or to prevent bleeding in those patients with abnormal
coagulation.
• Contains all the coagulation factors and albumin.
• Source of plasma cholinesterase.
Collection and Storage of FFP:
• FFP is collected as supernatant after centrifugation of whole blood.
• It Is frozen within 8 hrs and may be stored upto 1 year at -30⁰C, thus
minimizing the loss of Factor V and VIII .
• Brittle and handled with care.
• Thawed using a dry oven (10min) / microwave (2-3min) / water bath
(20min).
• Best used immediately / stored at 4⁰C & infused within 24 hrs.
18. Recommendation for FFP transfusion
• Correction of excessive microvascular bleeding in presence of PT > 1.5
times normal & INR > 2.0 or aPTT > twice normal.
• Correction of excessive microvascular bleeding that is secondary to
coagulation factor deficiency in patients transfused with more than one
blood volume (approx 70 ml/kg) and when PTT or INR cannot be obtained
in an appropriate amount of time.
• Urgent reversal of warfarin therapy when human prothrombin complex is
unavailable.
• Correction of known coagulation factor deficiencies for which specific
coagulation factors concentrates are unavailable.
• Heparin resistance (antithrombin III) deficiency in a patient requiring
heparin.
19. FRESH FROZEN PLASMA
• FRESH FROZEN PLASMA:
Fresh frozen plasma (FFP) is that is separated from whole blood
and is frozen within 6-8hrs of collection.
FFP contains plasma proteins & all coagulation factors, including
labile factors V andVIII, if stored at -30⁰C
• Indications for FFP:
-Actively bleeding multiple coagulation defeciencies
as in liver diseases.
-Disseminated intravascular coagulation (DIC)
-Coagulopathy in massive transfusion
-Thrombotic thrombocytopenic purpura (TTP)
-When specific disorder cannot be identified
-Familial factor V deficiency if conc. Factor not available
-Deficiency of factors II, VII, IX, X (vit.K deficiency or coumarin
overdose) if bleeding
- Antithrombin III deficiency
-Congenital / acquired coagulation factor deficiency
-Use of FFP with RBC’s has largely replaced fresh blood.
20. • Dosage of FFP:
• Should be given in doses calculated to achieve a minimum of 30% of plasma factor
concentration – achieved at 5-15ml/ kg body wt
• 5-8 ml/kg is usually enough for urgent reversal of warfarin therapy.
• The quantity of coagulation factors provided by 1 unit of FFP ~ those provided by
– 4-5 units of platelet concentrates.
– 1 unit of single donor platelets.
– 1 unit of fresh whole blood.
FFP is also treated with methylene blue to reduce the risk of viral infection
especially in the case of vCJD transmission
Must be thawed at 30 – 37⁰C in water bath
Must be used within 12hrs if stored at 2-4⁰C.
Monitor by post transfusion aPTT, PT & Fibrinogen
Must be ABO compatible but not group specific. Donor plasma should not contain
antibodies that might interact with A or B on recepient’s RBC’s.
21. Contraindications for the use of FFP:
- Blood volume expander
- Hypoproteinaemia
- Source of immunoglobulins
- When PT is < 18 seconds.
22. CURRENT STATUS – FFP IN CONFLICT/
DISASTER ZONES:
Fresh frozen plasma in a frozen plasma prepared
from fresh plasma. FFP is provided on battle field at
Combat Support Hospitals tp provide replacement of
clotting factors in severly bleeding battle casualties.
FFP that has been Thawed Plasma (TP) may be
provided at the Forward Surgical Teams. However
upto 40% units breaking during transhipment (on
dry ice) and the logistics involving substantial
weight, power and cube in theatre because of
inherent need to maintain it in frozen state.
23. Freeze Dried Plasma (FDP) - benefits to war fighter.
• Freeze Dried Plasma does not require shipment on
dry ice and is packaged in ruggedized containers.
These factors substantially reduce breakages and
waste of vital medical products during shipment to
and across rugged terrain in battle field.
• It has been used later part of 2nd world war and
subsequent conflicts and peace keeping missions.
• Many countries have their strategic production
units including ours.
24. Freeze Dried Plasma (FDP)
From Shelf
5 Minutes for
reconstitution
To Infusion
25. - Recent American and French forces in Afghan war
has shown seriously injured with massive
hemorrhage in shock and coagulopathic state which
require RBC and plasma in ratio 1:1. FFP requires
thawing and badly fits emergency for overseas
operations and poorly developed chain of evacuation
to Regional Trauma Centres. Refinement of the
product to render it more safe has been an ongoing
process till date.
26. FDSP (Freeze Dried Secure Plasma):
• Dilution and neutralisation of natural anti A and
anti B haeagglutinins.
• Further securization process is quarantine in which
donor is retested after a period longer than window
period of known viruses.
• This is compatible with all RBC and most ideal
universal donor AB plasma.
• At ambient temperature fibrinogen and all other
clotting factors are equal to FFP upto more than 2
yrs.
27. -Quarantine may be dispensed if technology for
pathogen inactivation exists.
-LyPTM – autologous freeze dried plasma could
be prepared for each combatant and be included
amongst his equipment.
-Pathogen inactivation – Ceras corporation in
USA has developed INTERCEPT BLOOD
SYSTEM technology to render blood products
pathogen free.
28. • SINGLE DONOR & CRYOPRECIPITATE – POOR
PLASMA:
- Plasma prepared from one unit of whole blood before
days of expiration is single donor plasma.
Cryoprecipitate poor plasma is byproduct of
cryoprecipitate preparation.
- Both lack the labile coagulation factors V and VIII
but contain factors II, VII, IX & X.
Indications:
-Deficiency of stable clotting factors (e.g warfarin
drugs)
-Burns
29. CRYOPRECIPITATE
• If FFP is thawed to refrigerator temperature (4° C), cryoprecipitate is
formed which is rich in high molecular proteins – Factor VIII, von
Willebrand Factor and fibrinogen.
• Viral infection risk is as for whole blood.
• Administered through blood filters.
Collection and Storage:
• Cryoprecipitate is prepared in volumes of 20-40 ml in the UK and Ireland.
• 1 unit of whole blood provides 15 ml of Cryoprecipitate.
• 1 pack contains at least 150-300 mg of fibrinogen and 70 IU of Factor VIII.
• Usually issued by the hospital blood bank in 10 prepared units (300ml
volumes).
• May be pooled in 1 bag.
30. Cryoprecipitate
Recommendations of Cryoprecipitate transfusion
Transfusion of cryoprecipitate is rarely indicated if fibrinogen
concentration > 150mg/dl.
Indicated when fibrinogen concentration is less than 100mg/dl in
the presence of excessive microvascular bleeding.
Indicated to correct excessive microvascular bleeding in
massively transfused patients when fibrinogen concentration
cannot be measured in a timely fashion.
Indicated for patient with von Willebrand disease and congenital
fibrinogen deficiency.
31. CRYOPRECIPITATE:
Cryoprecipitated proteins derived from FFP which
contains factor VIII, von-Willebrand factor, factor XIII and
fibrinogen.
Indications:
-Hemophilia A
-von-Willebrand disease
-Congenital/ acquired fibrinogen deficiency
-Acquired factor VIII deficiency (e.g DIC, massive
transfusion)
-Factor XIII deficiency
-Source of fibrin glue as topical hemostatic agent in surgical
procedures
Administration - of factor VIII conc, 500 IU/vial, available as
pharmaceutical products is choice for most hemophilias.
32. -Cryopreservation and lympholisation of platelets
and platelet substitutes are all being studied as
remedies for the short span of platelet
components.
- FFP and cryosupernatant are being used in
Therapeutic Plasma Exchange (TPE). This
removes much of von-Willebrand factor. Its
multimers leaving vWF enzyme to degrade
existing multimers.
- Blood substitutes have been advanced as remedies
for some of the complications with component
transfusion.
- Gamma radiated RBC’s are used to prevent
GVHD in severely immunocompromised,
lymphoma, BM/ SC transplants & Intrauterine
transfusions.
33. TRANSFUSION SUPPORT FOR STEM CELL/BONE MARROW TRANSPORT
PATIENTS
• Peripheral Blood Stem Cell/Bone marrow transplant
in hematological malignancies, solid tumors and
genetic disorders.
• Allogenic /autologous.
• Irradiated blood products reduce Graft V/S Host
Disease.
• Prevent alloimmunization – leucodepletion.
• CMV Antibodies in India approximately 98% and
hence difficult to find seronegative donors and hence
CMV prophylaxis only by leucodepletion.
34. Uses of plasma derivatives
Human Albumin Solution /
Plasma protein fraction
• It is also prepared by the fractionation of pooled plasma (
where all cellular and coagulation factors are removed).
• Available either in 5% or 20% (salt poor albumin) solution.
• Both contain 140-150 mmmol/ sodium (the latter contains
less sodium per gram of albumin).
• Heat treated to kill viruses.
• Shelf life of 2 years and stored at room temperature.
Uses :
• It is given to restore or maintain blood volume in the
patients who has hypovolemia without acute blood loss.
• In emergency treatment of shock due to trauma,
hemorrhage,surgery or infection.
• Also given in hypoproteinaemic conditions particularly
when edema is present.
35. Uses of plasma derivatives
Immunoglobulins
Proteins secreted by plasma cells. Involved in immunological defence systems.
Administrated to human and are obtained from
Pooled Human Plasma
1. Human Normal Immunoglobulins
• Used as long term replacement for missing/poorly functioning immunoglobulins, in proteins with
antibody deficiency disorders and also, in short, high dose courses, as immunomodulatory agents in
a range of autoimmune or inflammatory diseases.
• May be given I/M for the prophylaxis of certain infections e.g measles, hepatitis, rubella in
pregnant women. Some forms are given I/V as replacement therapy in immunodeficiency and in
various immune related disorders.
2. Hyperimmune Immunoglobulins
• Obtained from donors with high titres of specific antibodies and are used for passive immunization
against particular infections or to avoid potentially harmful immune reactions.
• Given I/M and are available against hepatitis B, tetanus,rabies, Rhesus D Antigen and herpes
viruses. They are screened for hepatitis and HIV infection.
36. Uses of plasma derivatives
Immunoglobulins
Immunomodulatory therapy with high dose Intravenous
immunoglobulin (IVIG)
• IVIG is sourced from a plasma pool of 1000-10,000 donors and
provides polyclonal immunoglobulins to a wide variety of
pathogens.
• Mechanism of action includes blocking of IgG binding Fc receptors
on macrophages, antiinflammatory effects and effects on T and B
lymphocytes.
• The product is expensive and scarcely available.
37. Uses of plasma derivatives
Immunoglobulins
Conditions where IVIg may benefit include :
Primary immunodeficiency
Guillain Barre Syndrome.
Chronic Inflammatory Degenerating Polyneuropathy,
Myasthenia Gravis.
Polymyositis
SLE
Kawasaki’s Disease
Neonatal Sepsis and Toxic Shock
Pemphigus
Rheumatologic Autoimmune disorders
38. Uses of plasma derivatives
Hemolytic disease of the newborn (HDN) and Anti RhD Immunoglobulin (anti-D)
• Rh D Antibodies are acquired during pregnancy/ tranfusion of Rh +ve cells to Rh -ve recipient.
• Use of anti RhD immunoglobulins has considerably reduced it.
• Anti-D Immunoglobulins is prepared from plasma of donors who have high levels of anti D following RhD
+ve cells during pregnancy or intentional immunization.
• Anti D products contain specific levels of anti D & can be given I/M or I/V destroys Rh +ve cells to
prevent maternal Rh Antibodies. It is given as
– Rh –ve woman are expose d to Rh +ve cells entering maternal circulation. e.g following trauma.
– Prophylaxis for Rh –ve mothers at 28 weeks and 32 weeks respectively and in case of fetomaternal
hemmorhage.
– Higher dose if increase RBC from fetus is more.
– Recurrent APH – further doses six weekly intervals.
39. Uses of plasma derivatives
Coagulation factor concentrates
Could be tranfused individually to treat specific
factor deficiency. These include –
• Recombinant Factor VIII and Factor IX
Most severe haemophiliacs receive it by
recombinant gene engineering technology in
countries like UK and the West.
Risk of viral infections is less.
• Factor VIII and Factor IX concentrate
Concentrates produced by fractionation of large
pools of plasma.
Current licensed products are all treated to
inactivate viral infections and are not reported
to transmit hepatitis or HIV.
Plasma/Cryoprecipitates are used to treat
haemophiliacs in many parts of the world due to
unavailability/high cost of plasma derivatives.
Commercially produced factor concentrates such as
"Advate", a recombinant Factor VIII, come as a white
powder in a vial which must be mixed with sterile
water prior to intravenous injection.
40. Uses of plasma derivatives
Coagulation factor concentrates
• Factor II, VII,IX,X concentrates [Prothrombin
complex concentrates (PCC)]
Main indication for this is Warfarin overdose
where there is life-threatening bleeding.
Used in patients with hemorrhage, particularly
when there is contraindiction to the use of FFP,
but it has not been tested in clinical trials in this
situation.
Doesn’t contain Factor V or VIII.
41. Uses of plasma derivatives
Coagulation factor concentrates
• Recombinant Factor VII a (NovoSeven®)
• Originally developed for use in haemophiliac patients with
inhibitors to factor VIII / IX of clotting cascade.
• Works by activating coagulation and platelet adhesion but only if
time factor is exposed.
• It has a local effect with no action on systemic coagulation factors.
• Its use in major secondary hemorrhage is unlicensed due to risk
of thrombotic complications.
• These drugs are extremely expensive.
• Other indictaions are still being established.
42. Apheresis
• Process of removal of whole blood from the donor /patient
separating it into various components followed by
retention of desired or unwanted components while the
remaining consitituents are reinfused back into the
donor/patient.
The following terms are used according to the material
retained :-
Plateletpheresis – where platelets are retained.
Plasmapheresis – when plasma is retained.
Leukopheresis – when white cells are retained.
43.
44.
45. Indications for Apheresis
A. Collection of components from healthy donors
• Plateletpheresis.
• Plasmapheresis.
• Leukapheresis.
• Erythrocytaphersis.
• Neocytapheresis.
• Peripheral blood stem cells.
B. Removal of pathological components from plasma
• Therapeutic plasma exchange.
• Therapeutic leukapheresis.
• Therapeutic thrombocytapheris.
• Therapeutic red cell, exchange.
46. Techniques used in Apheresis
Manual Method
• Performed using refrigerated centrifuges and specialized plastic bags.
• Blood collected in the primary bag is centrifuged to separate the desired
component which is retained in the satellite bag and the remainder is
reinfused through the same vein back to the donor.
Advantages:
• Simple and less expensive method.
Disadvantages:
• The amount of component prepared per procedure is less than that collected
from cell separators.
• The risk of returning red cells to the wrong patient if stringent donor
identification is not done.
47. Techniques used in Apheresis
Cell separators
Apheresis machines using centrifugal force and differing
densities of various blood components is used for
separation of desired components.
Types
a) Intermittent flow centrifugation (IFC)
e.g. - Hemonetics V-50, S-30, MCS
a) Continuous flow centrifugation (CFC) - Fenwal CS
3000, e.g. - Fenwal CS 3000 plus, Amicus, COBE
Spectra.
48. Donor Selection for Apheresis Procedure.
Plateletpheresis donors
• Donors should be healthy individuals meeting the standard
criteria for normal blood donation.
• Donor must have a minimum platelet count of 1.5 x x 10 5/μL.
• The interval between two procedures should be at least 48
hrs and the amount of red cell loss should not exceed
25ml/week.
• The donor should not have taken salicylates and antiplatelet
drugs for the last 72 hrs.
• The validity of mandatory tested infectious disease markers is
taken upto 3 days, if a repeat procedure is done in that
timeframe.
49. Donor Selection for Apheresis Procedure
Plasmapheresis donors
Serial plasmapheresis donors (donating at interval of less than 48 hrs) should:
• preferably be < 50 yrs of age & have had given blood previously one or two
occasions.
• Occasional plasmapheresis donors (no more than once in 4 weeks) are
accepted on the same criteria as mentioned for whole blood donation.
• Total blood count & total serum proteins should be within normal range.
• The maximum amount of plasma which an individual can donate in 1
sitting should not exceed 500 ml if the weight is between 50-65 kg & no
more than 900 ml if the weight is more than 65 kg.
• Adequate replacement fluids should be given to donor if >500 ml of
plasma is drawn.
• If the red cells are not reinfused back to the donor, the donor should be
deferred for 12 wks.
50. Apheresis
Leucapheresis
• Defined as removal of white cells with the return of red cells,
plasma and platelets to the donors.
• The granulocyte concentrate must contain minimum of 1.0 x
10 10/μL granulocytes in at least 75% of the units tested.
• The product should be transfused as soon as possible after
collection.
• The maximum shelf life is 24 hrs.
• The granulocyte collection yield by apheresis procedure (cell
separator) can be increased by
Increasing the granulocyte count of the donor by giving steroids or haematopoietic
growth factors.
By improving the separation with addition of red cell aggregating agents, e.g
hydroxyethyl starch (HES).
51. Apheresis
Neocytaphersis
In patients requiring repeated transfusions e.g Thalassemia
major, the administration of relative young cells.
Neocytes would improve the management of such patients by
decreasing the frequency of transfusion & rate of iron
loading. The neocytes for transfusion purposes are
prepared by the use of automated cell separator on the
principle that young, larger and less dense red cells are
expressed earlier than old cells.
Neocytes obtained in such a manner show improved survival
but are expensive and take approx. 3-4 hrs of donor time.
52. Apheresis
Erythrocytapheresis / 2 RBC collection procedure
• For collection of negative RBC units, e.g. O negative.
Advantages :
• Standardized RBC mass collection is possible.
• Metered anti-coagulant obviates mixing during collection, thus
reducing clot formation.
• Reduces the risk of hypovolemia to the donor.
• On line separation of RBC and plasma is possible
• Anti-coagulant to Whole Blood ratio is 1:16, thus decreases citrate
toxicity.
• Use of smaller gauge needle is possible.
Deferreal period
• After 2 RBC procedure, the donor is deferred for 16 wks.
53. Apheresis
Adverse Effects
Citrate toxicity may occur in the form of numbness & tingling
sensation around the mouth if the amount of citrate
infused exceeds the body’s ability to metabolize it.
The above problem is solved by
• decreasing the rate of infusion of anticoagulant
or
• by giving exogenous calcium to the donor.
Other adverse effects similar to that of normal blood
transfusion.
54. Apheresis
Therapeutic Apheresis / Therapeutic Plasma Exchange/Plasmapherisis
If 500 ml of plasma is removed without any replacement fluid, the term
plasmapharesis is used.
e.g to prepare anti- Rh immunoglobulin, donors are hyperimmunized to
Rh antigen. If more than the above amount is removed, the lost
plasma proteins is replaced by crystalloid and colloidal solution.
Replacement fluids for plasma exchange.
Exchange volumes vary between 1-1.5 times the plasma volume of the
patient.
55. Replacement
Replacement Advantages Disadvantages
Crystalloid •Low cost.
•No risk of disease
transmission
•No coagulation factors
•No immunoglobulins
•Hypo-oncotic
Albumin •No risk of disease
transmission.
•Iso-oncotic
•No coagulation factors
•No immunoglobulins
•Costly
Plasma Protein Fractions Less expensive than albumin. Induction of some
hypotensive action.
Fresh Frozen Plasma Maintains normal levels of
coagulation factors.
Immunoglobulin and plasma
protein.
Disease transmission if
not tested properly.
Citrate overload.
56. Current Research and Trials
• Donor lymphocyte infusion is a new use for lymphocyte fraction obtained from apheresis.
• Red cell substitutes are coming up and several sources of haemoglobin based enhanced oxygen carriers
are currently in Phase III Clinical trials in South Africa. These include Bovine Hemoglobin based oxygen
carriers (HbOC) and Perfluorocarbon based red cell substitutes.
• Intravenous Immunoglobulins (IVIg) has been used over 10 years.
• Immunotherapeutic approach to cancer therapy using dendritic cell vaccine is in phase II clinical trials.
• Cryopreservation and lyophilization of platelets and platelet substitutes - microspheres and IPMO
including infusible platelet membranes are all being studied as remedies for the short life span of platelet
components.
• FFP and Cryosupernatant (Cryoprecipitate reduced plasma) are being used in Therapeutic Plasma
Exchange (TPE). This removes much of vWF, its multimers leaving vWF enzyme to degrade exisiting
multimers.
• Blood substitutes have been advanced as remedies for some of the complications with component
transfusions.
• Gamma radiated RBCs are used to prevent GVHD in the severely immunocompromised , lymphoma,bone
marrow/stem cell transplants and intrauterine transfusions.
57. TO SUMMARISE
• Whole blood is a precious resource from which blood components
and plasma derivatives are obtained.
• Blood components include red cell concentrates, plasma
concentrates, fresh plasma & cryprecipitates. Plasma derivatives
include albumin, coagulation factors and immunoglobulins.
• The collection and storage of blood components and plasma
derivatives has many phases that are specific to type. These are in
place to ensure that the blood product is safe, effective and
economical.
• Transfusion of blood components and plasma derivatives is not
without risk in the immediate and long term perspective.
• Transfusion decisions require careful consideration of sound
pathophysiologic principles and comprehensive assesment of
patients risk factors in the immediate and the foreseeable.
Editor's Notes
The storage bags are made up of specific plastic, which allows gas exchange (for O2 & CO2 ) to occur across its walls at 22 ⁰C.
This helps preserve platelet function but promotes bacterial growth.
May be
ABO Compatibility in Platelet Transfusion o ABO antigens are expressed on platelet but variably and weakly. May give ABO incompatible platelets due to inventory issues. o Data suggest that ABO compatible platelet transfusion in general results in posttransfusion increments that are 25-30% higher. However, whether this clinically significant is debatable o In some recipients, poor response to platelet transfusion sometimes occurs due to faster clearance of ABO incompatible donor platelets; then it is not unreasonable to try ABO compatible platelets to see if response improves o Acute hemolytic transfusion reactions can also occasionally occur when platelets from a group O donor with high anti-A titer are given to an A recipient. Some centers have proposed either screening O platelets for high-titers of anit-A antibodies, or limiting exposure to O platelets in group A recipients. o Due to the small blood volume of neonates, exposure to ABO incompatible plasma should be minimized – use ABO compatible platelets only, or volume-reduce the plasma of non-ABO compatible platelets.
o Rh antigens are not present on platelets. They are expressed on RBCs o But platelet products may contain some contaminating RBCs with Rh antigens (In general, platelet concentrates have <0.5ml RBCs, apheresis platelets have far less)
o Alloimmunization to the Rh(D) antigen due to such a small amount of RBC occurs only rarely, so many places only try to give Rh compatible platelet products to female recipients o If due to inventory constraints, Rh positive platelet products are given to younger females (not past reproductive age), consider prophylaxis with Rhogam. Each full dose should cover exposure of ~15 ml RBCs
Double needle" procedures using both arms tend to be shorter since the blood is drawn and returned through different catheters; with "single needle" procedures a set volume is drawn and processed in the first part of the cycle and returned in the second part. The donor's blood undergoes repeated cycles of draw and return.
Many experimental approaches have been explored to produce hemostatically active novel human platelet products and substitutes capable of long-term storage. These include: platelet storage in the frozen state; storage in the cold (4 degrees C) in the liquid state; photochemical methods for the inactivation of viruses, bacteria and protozoa; infusible platelet membranes; and rehydrated lyophilized platelets. In addition to products using human platelets as their primary manufacturing source, other approaches have been used to make non-platelet-derived substitutes that might be capable of in vivo hemostasis. These include production of red blood cells, or liposomes, bearing hemostatically active agents on their surfaces; and fibrinogen-coated albumin microcapsules or microspheres. The development of platelet substitutes is an increasing scientific and technological endeavor and there are many reasons to believe that platelet substitutes will become more efficacious and safer to use over time. Ultimately, such work will result in safe and effective platelet substitutes being available for clinical use in thrombocytopenic or other patients with increased risk for bleeding.