17 - blood preservation

goals of blood preservation

goals of blood preservation

• maintain max viability/ function of each product

• eliminate physical changes that can damage product

• prevent bacterial contam

anticoagulant

prevents clotting

preservative

furnishes necessary nutrients for metabolism by cellular components

what will decrease in RBCs?

pH, 2,3-dpg, ATP, Na+

what will increase in RBCs?

K+, lactic acid, plasma hgb

what happens in plts?

• dec pH (lactic acid and CO2 production)

• shape (disk to sphere from pH change)

  • reversible is pH > 6.0

• anaerobic consumption of glucose = dec pH, function

  • agitation required for gas exchange

list the anticoagulants

ACD, CPD, CPDA-1, AS-1/3/5, heparin

ACD - acid citrate dextrose

• citrate: prevents clotting by binding Ca2+ and slows glycolysis

• dextrose: provides energy for rbcs

• acid: maintain pH

• popular until late 1950s

• 21 day storage

CPD - citrate phosphate dextrose

• improved rbc viability by increasing ATP

• maintains 2,3-dpg

• 21 day storage

CPDA-1 (citrate phosphate dextrose adenine)

• adenine: substrate for rbcs to produce ATP

• 35 day storage

AS 1 (adsol), AS3 (nutricel), AS5 (optisol)

• blood collected in std CPD

• spun and divided into PRP and pRBCs

• additive soln 100ml added to pRBCs to maintain levels of ATP and prevent storage hemolysis

  • saline, adenine, glucose to enhance survival/function

  • 42 day storage

heparin

• no preservative

• NOT for routine use

• unit only good for 48 hrs

rbc storage

• 1-6C

• fridge: continuously monitor, fan for air circulation, audible alarm system

rejuvenated rbcs

• PIPA: used on outdated or near expired units; restores Atp and 2,3-dpg; wash prior to transfusion

• PEP: restores ATP and 2,3-dpg

• uses:

  • freezing rare blood types or autologous units

  • may be used up to 3 days past expiration date

  • must be used in 24 hrs (open system) or frozen

frozen rbc procedure

• units < 6 days old

• glycerol method (low or high conc)

  • slowly add glycerol with agitation so it penetrates cells

  • high glycerol storage at > -65C (most common)

  • low glycerol storage at > -150C

frozen rbcs advantages

• long term storage (10 years)

• low number of leukocytes

• removal of plasma proteins

• allows for collection/storage of autologous units

• storage of rare units

frozen rbcs disadvantages

• prep time (before and after)

• expensive

• storage space

plt storage

• container with gas exchange

• random donor:

  • 20-24C + agitation 5 days (most common)

  • 1-6C + agitation 48 hrs

• pooled plts (open system):

  • 20-24 C + agitation 4 hours

• plt apheresis (closed system):

  • 20-24 C + agitation 5 days Or 4 hrs if open)

fresh frozen plasma (FFP)

• prepared from whole blood by differential centrifugation

• < 18C for 12 months; must freeze in 8 hrs of collection in CPD, CP2D, CPDA-1

• < 65 C for 7 yrs

thawed FFP

1-6C for 24 hrs (thaw at 30-37C in waterbath or FDA approved microwave)

liquid plasma

1-6 C for 5 days from date original product was thawed

cryoprecipitate

• prepared from FFP thawed at 1-6C; refreeze cryo w/in 1 hr

• storage < 18C for 12 months

other plasma products

• prepared from whole blood not used to make FFP

• manufacturers use purification and fractionation techniques to make:

  • albumin product

  • plasma proteins

  • coag factors

granulocytes

• 24 hrs at RT

• no agitation; irradiated prior to tranfusion

neocytes

• young rbcs with survival rate of 30-60% longer than normal pRBCs

• prepared by apheresis or automated cell processor techniques

• uses:

  • pts chronically tranfused (thals)

    • iron overload less likely using these cells

shipping of blood products

• check appearance and take temp prior

• liquid RBC: maintain 1-10 C

• frozen products: maintain frozen state (dry ice)

• plts: keep at RT

bacterial contam testing

• no method is sensitive to detect right after donation

• common methods: BacT/ALERT, pall eBDS system, ScanSystem

• approved for leukocyte reduced aphresis plts

• some approved for testing pools of leukocyte reduced whole blood derived plts

• none used for routine screening of whole blood derived plt concentrates

bacT/ALERT

• requires plt component stored at 24 hrs before sampling

• 4-8ml withdrawn from unit and inoculated into aerobic bottle and/or anaerobic bottle

• if neg after 12-24 hrs: component is released but keep incubating for shelf life of unit

• if pos: send for ID

  • if unit released: retrieve unit and resample

pall eBDS and ScanSystem

culture based tests using optical scanning to detect bacteria

plt PGD test

• bacterial screening prior to issue

• rapid strip IA for Ags

• FDA approved for sole bacteria of whole blood derived plt concentrates that are pooled prior to use