Blood Components and Transfusion Practice Flashcards
Hemovigilance
Consists of the collection of information on the complications of transfusion, analysis of these data, and subsequent data-driven improvements in transfusion practices. Goal: to improve the reporting of transfusion-related adverse events.
Why irradiate
- Premature Neonates <1200g 2. known or suspected cellular immunodeficiency 3. significant immunosuppression (chem/radiation) 4. components from blood relatives 5. HLA/crossmatched plt 6. Granulocytes
How much radiation
1500 (for the entire bag) 2500 directed at the center of the bag
Why perform exchange transfusion vs. simple transfusion
In sickle cell to prevent iron overload from multiple units transfused.
What time of patient has highest rate of alloimmunization
Sickle Cell Disease Patient
How do you treat iron overload in neonates
Chelation therapy
Why leukoreduce blood
decrease risk of CMV, decrease HLA alloimmunization, preven febrile nonhemolytic transfusion reaction
volume reduction washing
decrease plasma in products for patients that cannot handle increased vascular volume (renal ischema, compromised heart function
Do units labeled Rh positive require confirmation testing of whole blood group
only require front type A and B, do not require Rh typing, D negative labeled however do require D typing (do not require weak D testing)
How is cryoprecipitate made?
Must come from WB derived plasma, the plasma is frozen and then ‘slow thawed’ at 1-6 degrees. Certain elements are not soluble at 1-6 degrees and therefore precipitate. This is then cold centrifuged and the supernatant is pulled off the top leaving 10-15 mL.
Cryoprecipitate contains which factors?
Fibrinogen, Factor VIII, vWF, fibronectin, Factor XIII
What are the requirements for Factor VIII quantity per bag
80 IU per bag
What is the requirement for quantity of fibrinogen in cryo bag?
150mg of fibronogen per bag.
Component preparation from WB 1st step
Red Cells step 1 soft spin, platelets are suspended in plasma (platelet rich plasma) and is transferred to a second bag, red cells remain in original bag and additive solution is added to bottom layer ( AS-1 AS-3 AS-5)
Component preparation from WB 2nd step
Platelets step 2 hard spin, this packs the platelets. platelets in one bag with 50-70mL plasma, supernatant plasma transferred to a different bag.
Component preparation from WB 3rd step
Plasma must be frozen, if frozen with 8 hours called FFP, if frozen within 24 hours PF24
PF24
Plasma Frozen within 24 hours of phelebotomy
FFP
fresh frozen plasma, frozen within 8 hours of collection.
Cryo production
Frozen Plasma (must be WB derived) thawed at 1-6c. Hard spin AT 1-6C, the cryo-reduced plasma transferred out leaving ~10-15mL in the cryo bag
Indications for Red Blood Cell Transfusion
to treat SYMPTOMATIC anemia in patients who need an increase of oxygen carrying capacity and red cell mass
Typical Hgb levels for transfusion
<6g/dL usually requires transfusion >10g/dL usually does not require transfusion
Washed RBCs
prevent severe allergic reaction, to remove IgA in IgA deficient individuals or haptoglobin in haptoglobin deficient individuals
Frozen RBCs
for use in rare red cell units, or autologous units
Laboratory tests for platelet functin
platelet aggregation test, platelet count, NOT BLEEDING TIME
Platelet contraindications
do not transfuse platelets to patient with conditions of rapid platelet destruction: ITP, DIC, HIT, TTP. definitely not HIT or TTP- could cause thrombosis, DIC is subjective depending on the level of clotting vs. bleeding, cryo is more appropriate. ITP does need platelet transfusions however the concern is recurring destruction and damage to spleen, in spleenectomy of these patients platelets can be given once the vascular pedicle is clamped
One does (1 apheresis or 5-6 pooled donors) will raise platelet count how much?
30-60k in an adult
Volume of apheresis platelet
200-400 mL
QC requirement for platelet
3 x 10^11
Advantages of apheresis platelet vs. pooled donor
can provide matched-HLA type, wouldn’t be able to find 5-6 donors in order to provide a full unit, also can reduce the donor exposure with number of HLA antigens/HNA/HPA the patient is exposed to.
Platelet transfusion count indications
10,000/uL standard in most places, 50,000uL in active bleed or surgical patients 100,000/uL in patients with intacerebral damage or surgery
If thrombocytopenia is due to sepsis or fever
Platelet transfusion is largely ineffective, need to treat sepsis
non-immune causes of Platelet refractory
massive bleeding, splenomegaly, fever, sepsis, DIC, drugs and patient related (chemo)
drugs that can cause platelet refractory
amphotericin B and vancomycin
why is it important to give type specific or compatible platelets
- Because platelets carry ABH antigens, if an A platelet is given to an O patient, the anti-A in patient can destroy the platelets- not as much of a bump 2. Because Platelets have antibodies if you give an O platelet (with anti-A) to an A patient it could bind to red cells and DAT may be positive, hemolysis is pretty rare.
platelet type to give baby
match the babies blood type, however if baby had HDN due to ABO antibodies (ex. anti-A from mom) you would want to give O platelets instead
platelet transfusions: bloody platelets
If Platelet has > 2mL of red cells- you must crossmatch, this will be grossly bloody
platelets: Rh
there are not RH antigens on platelets, however, there are red cells in platelets, try not to give RH pos platelets to an Rh negative patient, could make anti-D (if unavoidable you can give RHIG- (in women of child-bearing age especially) 1 Rhig vial is enough to protect against D positive Red cells in 7 apheresis platelets or 30 individual platelets
Thawed plasma
FFP/PF24 thawed but not transfused within 24 hours can be relabeled to ‘thawed plasma’ All of these contain therapueutic clotting factors including V and VIII
Contraindications for plasma transfusion
Do not transfuse when coagulopathy can be corrected more effectively with specific therapy: factor concentrates, Cryo or vitamin K
Uses for plasma in transfusion
- Reversal of warfarin (second choice behind PCC) 2. massive transfusion 3. preoperative or bleeding patients with multiple factor deficiencies (liver diease, DIC, dilutional coagulopathy due to massive transfusion)
Dose of plasma
~10-15 ml/Kg
What percentage of factors are necessary for normal hemostasis?
40% of factors need to be present
what volume of plasma has 100% factor activity
1 Liter
how much does each FFP unit raise coagulation factors in adult
10% (if you think patients approx plasma volume ~3000, each plasma unit ~300 and each unit contains 100% factor this equals 10%)
Liquid plasma
plasma separated any time up to 5 days AFTER expiration of the whole blood, stored at 1-6 degrees. Expiration: CPD=26 days CPD-A1 40 DAYS, indicated for treatment of massive hemmorhage. This is only good for 5 days after WB expiration date, if it’s separated 5 days after expiration it expires that same day.
Cryo reduced plasma
by product of cryo productin, deficient in fibrinogen, factor VIII, factor XIII, vWF, may be used in therapeutic exchange for TTP
recovered plasma
Includes plasma (frozen) and liquid plasma. unlicensed not for transfusion, expiration depend son short supply agreement, used for fractionation into albumin, AT-III, Factor VIII, IX, or immunoglobulin.
Short supply agreement
When Recovered [] Plasma is to be used in licensed products, it must be shipped in full compliance with the provisions of 21 CFR 601.22 (Short Supply) by the short supplier (the initial manufacturer) or an authorized agent (the licensed manufacturer’s agent) solely to the manufacturer under whose license the short supplier or an authorized agent is on file. Recovered [] Plasma for use in manufacturing licensed products may be pooled by the short supplier if complete records, including donor numbers for each unit pooled, are maintained. Any product manipulated by an authorized agent cannot be shipped under the short supply provisions.
each unit of cryo typically has how much fibrinogen
~250mg/dL
What is cryo used for
For Factor XIII and fibrinogen deficiency. Not used for Factor VIII deficiency or vWF when concentrates are available
How much does cryo increase fibrinogen level
single unit (5-10 mg/dL) pooled pack of 5 (25-50mg/dL)
Reasonable fibrinogen target for patient
150-200 mg/dL
Granulocyte Transfusion indications
immunocompromised individual severe neutropenia (<500 granulocyte count), fever for 24-48 hours, bacterial/fungal culture positive, not responding to antibiotics myeloid hypoplasia, MUST HAVE REASONABLE CHANCE FOR RECOVERY, CGD during life-threatening epidsodes of infection. This is rarely used in adult patients.
normal WBC
4.5-11 x10^9
aPTT and PTT normal range
aPTT is the same test as PTT except an activator has been added, cutting the response time in half RR for aPTT is 30-40 seconds PTT is 60-70 seconds
PT normal range
10-12 seconds
Granulocyte collection
apheresis collection, donor is stimulated (G-CSF) for a larger yield side effect is musculoskeletal pain. collect 250-600mL, store at RT for 24 hours
Acceptable granulocyte collection value QC
> /= 1 x10^10 granulocytes
Setting up granulocytes on patient
unit needs to be irradiated, prevent TA-GVHD also crossmatch is required, it contains >2mL of red cells. When transfusing DO NOT use a leukoreduction filter, defeats the purpose. CMV- donor if indicated, since you cannot leukoreduce, if patient is alloimmunized use HLA-matched products
Leukocyte reduction requirements
<5 x 10^6 residual WBCs per product- deemed by the FDA.
Benefits of leukoreduction
Decrease risk of CMV infection/effects, decrease exposure to further antigens HNA, HLA, decrease febrile nonhemolytic reactions. It is an alternative to CMV sero-negative.
Indications for leukoreduction
- immunocompromised patients (newborns, transplant recipents and patients with aplastic anemia) 2.recurrent febrile non-hemolytic transfusion reactions and 3. prevention of HLA alloimmunization.
Irradiation importance
The only currently accepted method in the US for preventing TA-GVHD.
classic cause of TA-GVHD
donor is homozygous, but recipient is heterozygous, does not recognize the homozygous as different because it matches one of it’s own, but the donor cells see the recipient as foreign.
Irradiation amount and QC
must receive >25 centigrade to the midline of the bag, >15 centigrade to all other parts of the bag.
AABB standards for irradiation
- patient is identified as being at risk for TA-GVHD 2. cellular units from the recipients blood relatives 3. donor is selected for HLA compatibility.
Freezing and Deglycerolization of RBCs
- open system: unit expires within 24 hours of thaw stepwise decreasing osmolar solution of saline: 12% NaCl 1.6% NaCl .9% NaCl. 2. close system, expires in 14 days, must freeze and deglycerolize using the same system
Deglycerolization of RBCs QC
cells must have >/= 80% recovery
Deglycerizatin and sickle cell
sickel cell trait donors should not be frozen because there is major cell loss when deglycerolized with hypertonic wash solutions.
expiration of deglycerized cells open system
24 hours
expiration of deglycerized cells closed system
14 days
Derivatives examples (6)
Albumin, Prothrombin Complex Concentrates (vitamin K dependent factors), IVIG, RHIG, Clotting factor concentrates (VIII and IX) and Antithrombin III
cohn fractionation
The Cohn fractionation process originally developed in the 1940’s involved modifying the pH, the ethanol concentration and the temperature of the plasma to separate its proteins through precipitation into five “fractions” (I-V).
derivatives processing
cohn fractionation and then further processed to purify and concentrate teh proteins using chemical solvent/detergent and affinity column
Premature infant TBV
108
Newborn infant TBV
87
Blood administration filter
all blood components need to be filtered using standard filter (170-260 microns)
Venous access gauge, in adults and chilren
adults: 18-20 gauge children 22-24 gauge
Standards for Physcian orders
must order component preparation from blood bank, then must order transfusion, including premedication or component modifications
Prior to transfusion checks
verify MD order, two independent recipient identifiers, component number, abo and rh check of both the unit and the recipient. Component tag must stay attached during the transfusion! Component check: check the experience of hemolysis clots, and color, also check the expiration date
IV solutions
0.9% sodium chloride, normosol-R pH 7.4, plasma lyte A, pH 7.4. Plama-Lyte 148
Must do’s during transfusion
Begin unit slowly 2mL/min and check vitals at 15 minutes. After 15 minutes you may increase the transfusion rate, monitor vitals periodically until transfusion is complete, must complete transfusion within 4 hours
Pathogen inactivation
Inactivates viruses bacteria, spirochetes, parasites and leukocytes. T cells are reduced to a level that potentially lowers the risk of TA-GVHD.
Bacterial Detection of platelets
Without pathogen inactivation, detection must be culture based. 1. Pall eBDS:surrogate marker of oxygen concentration 2. BacT alert surrogate marker=CO2 3. verax PGD, 30 minutes bench top quantitative immunoassay
How long is blood good for post irradiation
28 days or original unit expiration date whichever is shorter
Number of WBCs required for blood to be considered leukoreduced
5 x 10^6 (normal WBC ct in unit is 5x10^9)
When transfusing blood to patient, what does the clerical information listed on the recipent transfusion tag get compared to?
The hospital issued wristband on the patient.
What two things must the blood request form contain?
Patient unique ID number and First and Last name
Should draw the patients blood only after what?
Verifying the patients identity by the wristband, or the patient providing their name and dob. Should not use the name on the bed or chart as this may not be the correct patient.
In babies how old of blood can be provided
As fresh as possible and no older than 7 days
Massive Transfusion definition
8-10 RBC units in 24 hours or 4-5 units in 1 hour
Massive tranfusion in patient with antibody
Once blood volume has been surpassed there should be a work-around to shorten the pre-transfusion testing time on the units, no longer have to provide antigen negative until bleeding has significantly slowed down, at this point patient’s titer can increase and they may hemolyze donor cells that have the antigen
Counteracting the effects of heparin
protamine sulfate
Autologous units- testing on the unit
Must test the ABO and RH groups but does not need infectious disease testing or tests for unexpected antibodies-when blood is used within the collecting facility. Unit must be labeled ‘For autologous use only”
In vivo compatibility of donor units can be measured by:
Labeling with radioactive (technetium)TC-99M or CR51 (chromium), blood transfused slowly and patient monitored closely, can later measure how much of RBC survived in patient with radioactive labels
MSBOS
maximum surgical blood ordering schedule- was developed in order to better track what surgeries should or should not be ordering blood and how many units. Helps to prevent wastage of additional units that did not need to be ordered.
After pretransfusion testing has been completed what two records must be prepared?
A statement of compatibility must be retained as part of the patient’s permanent medical record-if blood is transfused. A second label or tie tag must be attached to the unit stating the intended recipients identity, the pretransfusion testing results and the donor unit number-this tag must remain on unit until after completion of the transfusion.
RFID
radio frequency identificaion, contains specific informatin that can be used for tracking and to communicate teh specific information. For example patient wristbands that contain the patient MRN and name can be scanned via barcode and transmitted to a computer system.
How many times the information need to be reviewed as the clerical check at patient bedside prior to transfusion
at least twice. i.e. initial read and then ‘read back’ verification, two different sets of eyes.
cannot accept unit back into inventory after issue if temperature is:
less than 1 degree C or above 10 degree C
prestorage leukoreduction gets rid of how many WBCs from original product
99.9%
WB hct
38%
Ideal hct for RBC unit
less than 80% (80% maximum)
HgB of final RBC unit
50-80g
Irradiation sources
Cesium 137 and cobalt 60
Final RBCs volume
typically 160-275mL in bag
used for volume expansion
saline, albumin and plasma
platelets, WBCs and clotting factors in WB
they don’t survive, this is why whole blood is not used much anymore
Testing for syphillis-why
Serological test for syphillis is done because it is associated with increased risk of HIV and Hepatitis if possible
How many cases of transfusion associated transmission of syphillis
three ever, doesn’t survive in citrated blood in 1-6 degrees for 72 hours- most likely transmission from platelets
RPR what it is
rapid plasma reagin -syphilis test
VDRL what it is
venereal disease research laboratory- syphillis test
Screening tests for syphilis
RPR and VDRL, both based off reagin or antibodies toward cardiolipin particles. Present in people with untreated syphillis infections. will agglutinate show visible flocculation.
Confirmatory test
FTA-ABS fluorescent treponemal antibody adsorption test, immmunoflourescence is used to detect antibodies to spirochette T. Pallidium.
If screening test is positive for syphillis
confirmatory test is then performed. negative confirmatory test- donor reentered and units labeled with reactive screening test. If positive unit is discarded and may be reentered after 12 months and documentation of completed treatment
If platelets are pooled within 4 hours of transfusion what testing is appropriate for bacterial testing
PGD- bacterial test, pregnancy test prior to releasing- testing 45 minutes can be performed at transfusion center
If platelets are prepooled what testing is appropriate for bacterial testing
culture based testing.
Steps if unit is positive for bacteria
quarantine and discard. If already issued need to recall and recipients physician is notified
RR of T. cruzii antibodies
indefinitely deferred all unit destroyed, there are currently no method for reentry as no confirmatory testing exists
If donor is positive for T. Cruzii antibodies
units must be discarded- “look back” to donations from the past 10 years on this donor, if donor had previously nonreactive test “look back” 12 months previous to the nonreactive test result
T. Cruzii testing- reasoning, amount of testing
If donor is testing and nonreactive no further testing needs to be done in future donation. most people in the US that are positive are chronically positive from previously living in endemic country
Random donor platelets should contain:
5.5 x 10^10 plts per unit
