Blood Donation Testing and component preparation

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Blood Donation Testing and component preparation
2014-01-27 22:15:51
Donors infectious disease testing components

allogenic and autologous donations, infectious disease testing, component preparation
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  1. Diversion pouch
    • diverts the first 30-45 mL of blood,
    • retains skin plug, and
    • prevents bacterial contamination
  2. Why plasma from low volume units cannot be transfused?
    because of the abnormal anticoagulant/plasma ratio
  3. why is knowing the specific gravity of different blood cells helpful?
    to develop centrifugal conditions for optimal cells separation and collection.

    needed to convert weight of component (g) to the volume (mL)
  4. What is the volume of blood collected during routine phlebotomy?
    450 +/- 10% or 500 +/- 10%
  5. arterial puncture
    • bright red blood
    • rapid collection (within 4 minutes)
    • pulsating needle
  6. Plasma frozen within 24 Hours after Phlebotomy
    plasma separated from WB and placed in the freezer within 8-24 hours
  7. 3 major variables that affect recovery of cells from WB by differential centrifugation are:
    • rotor size
    • centrifuge speed
    • duration of centrifugation
  8. Primary separation by centrifugation
    (soft spin)
    • PRP and RBCs are separated
    • PRP is removed into another container
  9. 2nd separation by centrifugation
    (hard spin)
    • Higher g forces used on PRP container
    • Platelets are turned into a pellet
    • PPP transferred to another container
    • pellet left in 40-70 mL of PPP for 1 Hr
  10. Shelf life and hematocrit of CPD- or CP2D-preserved RBCs
    • 21 days
    • Hct of 65-80%
  11. What amount of AS is added to RBCs?
    450 mL WB collection-->100 mL AS

    500 mL WB collection-->110 mL AS
  12. shelf life and Hct of CPDA-1 preserved RBCs
    35 days

    Hct <80%
  13. What is commonly used for neonatal or pediatric transfusions?
    CPD-preserved RBCs

    <7 to 10 days old
  14. What influences clumping in platelets?
    Temp at which they are prepared

    Platelets prepared at 24C , show least amount of clumps
  15. what amount of RBCs is present in a unit of platelets?
    • < or= 1.0 x 109
  16. What are the 2 major methods used in preparing platelets from WB?
    PRP method--->US

    • Buffy coat method-->Europe &
    • Canada
  17. Fresh Frozen Plasma
    plasma separated from WB and placed in the freezer within 8 Hrs of collection
  18. How can rapid freezing of plasma be accomplished?
    Blast freezer

    Dry ice

    Mixture of dry ice with either ethanol or antifreeze
  19. What can be done to an FFP bag before freezing, to recognize inadvertent thawing?
    Place a rubber band around the bag

    press a tube against the bag to create indentation
  20. which coagulation factors are reduced in Thawed Plasma prepared from FFP?
    Factor V (>60%)

    Factor VIII (>40%)
  21. Liquid Plasma
    Can be separated at any time

    stored at 1-6C for up to 5 days after exp of WB

    used as volume expander
  22. which factors are reduced in cryo poor plasma?
    • Factor VIII
    • vWF antigen
    • vWF activity
    • fibrinogen
    • Factor XIII
  23. which coag factors are found in normal amounts in cryo poor plasma?
    • Factor V
    • Factor I
    • Factor VII
    • Factor X
    • Antithrombin
    • Protein C
    • Protein S
    • alpha2-antiplasmin
  24. Recovered plasma
    • plasma for manufacture
    • unlicensed
    • processed into derivatives
    • has no expiration date
    • records kept indefinitely
  25. How is Cryoprecipitated AHF prepared?
    • FFP thawed to 1-6C
    • Cold-insoluble protein collected by centrifugation
    • Cryo poor plasma transferred to another bag
    • Precipitate is resuspended in 15 mL plasma
    • Frozen within 1 Hr of preparation
  26. Cryo AHF from which blood groups has higher leves of Factor VIII?
    • From blood groups A and B
    • 120 Vs. 80 IU (Group O)
  27. How are granulocytes prepared from WB?
    • 60 mL of hydroxyethyl starch (HES) is added to WB that are <24Hrs old
    • Allowed to rest 1 Hr
    • Gravitational force settles RBCs
    • plasma and buffy coat transferred out
    • plasma is centrifuged at 5000 x g for 50mins at 22C
    • 90% of plasma transferred back to RBC bag
    • 20mL of plasma is left with granulocytes
  28. Granulocytes
    • typically collected by apheresis
    • donors stimulated with corticosteroids
    • necessary to transfuse before infectious disease testing is completed
  29. What are the irradiation sources in use?
    gamma rays from either cesium 137 or cobalt 60 sources

    X-rays produced by radiation therapy linear accelerators or standalone units.
  30. What should be the irradiaton dose to the center of the irradiation field?
    at least 25 Gy (2500 cGy) and no more than 50 Gy (5000 cGy).
  31. Besides dose mapping, what should also be monitored periodically for gamma irradiators?
    • the turntable operation
    • the timing device
    • the lengthening of irradiation time caused by source decay
  32. For gamma irradiators, how often should verification of delivered dose be performed?
    Cesium 137--->annually

    Cobalt 60--->semiannually
  33. What are the three methods used to measure hemoglobin?
    • Copper-Sulfate density
    • Spun microhematocrit
    • Spectrophotometric measurament
  34. Which clotting factor deficiency is not a cause for donor deferral?
    Factor XII deficiency is not associated with bleeding or thrombosis.  Persons with this deficiency could donate.
  35. What are some of the desired properties of blood containers?
    • pyrogen free
    • flexible, tough, scratch resistant
    • able to withstand sterilization
    • allow adequate gas exchange
    • prevent evaporation of H2O from component
    • contains di-(2-ethylhexyl) phthalate (DEHP) to make it more pliable
  36. when is leukocyte reduction done on RBCs?
    • Usually within 72 Hrs
    • Always within 120 Hrs of collection
    • Residual WBCs shouldn't exceed 5 x 106
  37. what's the amount of platelets found in 1 unit?
    WB--->5.5 x 1010

    Apheresis---> 3.0 x 1011
  38. When are single-donor platelets generally indicated?
    patients unresponsive to random platelets due to HLA alloimmunization

    to limit platelet exposure from multiple donors
  39. which type of bags are commonly used for the high-glycerol RBC cryopreservation method?
    polyolefin bags  are less brittle at -80C
  40. Why is the high glycerol method for RBC cryopreservation preferred over the low-glycerol method?
    its simpler

    does not require liquid nitrogen
  41. How soon after collection should the glycerol be added to cryopreserve RBCs?
    within 6 days
  42. What is the storage temperature and shelf life of cryopreserved RBCs?
    -65C or colder

    10 years expiration
  43. What is the final solution in which deglycerolized RBCs are suspended?
    0.9% NaCL

    0.2% Dextrose

    • Dextrose provide nutrients and support posttransfusion RBC
    • viablitity for 4 days
  44. Rejuvenation solution is not approved for which RBCs?
    • For RBCs preserved in:
    • CP2D
    • AS-3
    • AS-5
  45. Why are RBCs rejuvenated?
    Storage of RBCs causes reduction in the intracellular levels of 2,3-diphosphoglycerate (2,3-DPG) and ATP
  46. Which principles apply for "serial" plasma collection?
    • Donors must give consent, and they must be observed closely during procedure.
    • RBC loss must not exceed 25mL/week
    • total protein and serum protein electrophoresis or quantitative immunoglobulins, should be within normal limits
    • 48 Hrs should elapse between procedures
    • No more than 2 in a 7day period
  47. Which corticosteroids are normally used to stimulate granulocytes donors?
    Oral prednisone 60mg (single or devided dose)

    Oral dexamethasone 8 mg
  48. what is hydroxyethyl starch (HES)?
    • common sedimenting agent
    • enhance granulocyte harvest by causing increased sedimentation of RBCs
    • Can be detected in donors for a year
    • colloid; acts as volume expander
    • May cause headaches or peripheral edema because of expanded circulatory volume
  49. For which infectious agents are there FDA-licensed confirmatory assays?
    HIV-1 antibody

    HCV antibody

  50. In which circumstance, can a repeatedly reactive unit be used?
    The syphilis screening assay (RPR) is the only situation in which negative supplemental test results, can permit use of a reactive unit.
  51. Why is ID-NAT recommended for screening of WNV?
    • viral RNA is often low in WNV infection
    • when donor samples are combined into minipools (MP-NAT), sample may become diluted below detectable level
  52. Which infectious agent, may be limited to one-time testing of each donor?
    T. cruzi antibody  (Chagas)
  53. Refusal of autologous units with positive test results, may be interpreted as:
    A violation of the Americans with Disabilities Act
  54. There are no screening tests for which infectious agents?

    variant Creutzfeldt-Jakob disease (vCJD)
  55. With NAT, what is the window period of HIV?
    9 days
  56. With NAT, what is the window period of Hepatitis C?
    7.4 days
  57. What is the window period of Hepatitis B?
    38 days
  58. What was the first retrovirus identified?
    • HTLV-1 was identified in 1978
    • Isolated from a cutaneous T-cell lymphoma patient
  59. What is a major cause of transfusion-related fatalities?
    • Bacterial contamination of blood components
    • Mainly platelets
  60. What is the process most commonly used to screen platelets for bacteria?
    BacT/ALERT culture system
  61. Which supplemental test for T. cruzi is very helpful?
    Radioimmunoprecipitation assay (RIPA)
  62. What is the most common Babesia species and what is the vector?
    B. microti

    vector is Ixodes scapularis (same tick that causes Lyme disease)
  63. Syphillis is caused by which spirochete bacterium?
    Treponema pallidum
  64. What are the 4 Plasmodium species that account for most malaria infections in humans?
    • P. falciparum
    • P. vivax
    • P. malariae
    • P. ovale
  65. What are prions?
    an infectious agent composed of protein in a misfolded form.

    cause fatal infections of the nervous system called transmissible spongiform encephalopathies (TSEs)
  66. CJD exclusions are for:
    • family history of disease
    • receipt of Pituitary derived human GH
    • receipt of dura matter tissue graft
  67. vCJD exclusions are for:
    • residence in the UK or Europe for specified times when mad cow disease was endemic
    • receipt of transfusion in UK or France
    • receipt of UK bovine insulin
  68. What is Pathogen Reduction Technology?
    Processes that reduce the infectivity of residual pathogens in blood components

    could reduce transmission of agents for which there are no donor screening tests

    further reduce the residual transmission risk of known agents

    Not approved in the US
  69. What are some methods used in Pathogen Reduction Technology?
    • prolonged heat
    • solvent/detergent treatment
    • nanofiltration
    • chromatography
    • cold ethanol fractionation
  70. What are some potentital problems in intraoperative blood salvage?
    air or amniotic fluid embolus risk

    hemolysis of processed blood from excessive suction in the operative field

    Coagulation factor activation
  71. What are some advantages of acute normovolemic hemodilution (ANH)?
    less hemoglobin loss

    decreased blood viscosity increases cardiac output and may improve oxygenation

    Coag factors and Platelets survive well for short periods  and help hemostasis
  72. DIC is associated with which autologous blood collection method?

    Shed blood has undergone coagulation, fibrinolysis and hemolysis