One unit of blood = 450 (just under a pint)
One unit of plasma = 50% of blood (normal Hct) so = 450 X 50% = 220 mL (200-250 mL)
- One unit of FFP = 220 mL
FFP is prepared from whole blood, separated by centrifugation steps from RBCs.
- Can be stored up to 1 year under -18 celcius.
- Need to be thawed for 37 celcius in waterbath for 30 minutes.
FFP has intrinsic INR of 1.5
1 mL of FFP has 1 U of clotting factors, 1 U (220 mL) therefore has 220 U of clotting factors
- BUT factor recovery of FVIII (most studied is literature) is only 40%, so 1 U of FFP can only recover ~ 88 U of clotting factors
- Vd in blood = 0.05 L/kg, in a 70 kg = 3.5 L
(3.5 X 88)/100 = 2-3%
- Therefore transfusing 1 U of FFP will only result in 2.5% raise in cotting factors.
- A change of coagulation status needs at least 10% raise in clotting factors, usual starting dose of FFP is 4 units.
250, 2.5, 15, 1.5 rule
- 1 unit of FFP = 250 mL
- 1 U increases clotting factors by 2.5%
- 15 cc/kg in adults
- Intrinsic INR = 1.5
- If thawed FFP is not used, it can be refrigerated (~5 celcius).
- Shelf life after thawing is 5 days (NOT 24 hours).
- Contains a slighly lesser amount of FV and FVIII but still therapeutic (clotting levels >30% of normal)
- FVIII tends to increase during stress events as it is acute phase reactants.
- For the great majority of situations, thawed plasma can be used interchangeably with FFP, except perhaps in DIC (severe consumptive coagulopathy).
- Thawed plasma reduce wastage of unusused FFP and can improve turnaround timer by eliminating the 30 minutes needed to thaw the FFP to 37 celcius.
Indications of FFP
Note: to have a clinically significant clotting factors deficiencies (levels <30% of normal), INR is >1.5:
- Documented clotting factors deficiencies eg liver disease, DIC, dilutional coagulopathy
- Reversal of warfarin bleeding (BUT NOT recommended for reversal of NOACs because massive volume will be needed ~10 units)
- For Hemophilia, factor concentrate should be used preferably.
- FFP but NOT thawed plasma can be used for Factor V Leiden.
- ABO Identical is better than compatible.
ABO compatible chart for plasma: AB is universal donor, O is universal acceptor; A can receive from A or AB, B can receive from B or AB
- No Rh status needed
- Free of leucocytes so no risk of acute rejection
Possible viral infectivity as it does not undergo viral inactivation
- Solvent-detergent FFP, SD-FFP (FFP treated with solvent and detergent)
– Lipid coated viruses eg HIV, HBV and HCV are eliminated, but not viruses which aren’t lipid coated eg HAV, EBV.
- When FFP is thawed slowly at 1-6 celcius, a precipitate is formed.
- Cryoprecipitate is also called cryoprecipitated anti-hemiphilic factor (FVIII).
- Contains most of the FVIII, vWF, fibrinogen and fibronectin.
– 100 U of FVIII and vWF
– 200 mg of fibrinogen
- Stored frozen. Must be transfused ASAP once thawed (within 4 hours)
– 4 hours if pooled units (cryo is often transfused as 4-6 units pooled.)- 6 hours if closed single unit
- Dose depends on the lab assay of coagulation factors.
– No specific dose, but generally 1 unit/10kg increases 1 g/dL of fibrinogen.– Each unit is around 10 mL
- ABO compatibility, but if unable, ABO incompatible can be used with caution
– Patient may have positive Coombs’ test and rarely hemolytic anemia
- Is the supernatal recoverred after cryo is made.
- For exchange transfusion eg in TTP
- Theoretically, better than FFP for TTP due to lack of vWF. But has not been shown to be superior.
- What’s the difference between fresh plasma and fresh frozen plasma?
– Not much, except that FP has slightly low level of FV and FVIII