Blood Products Flashcards
Rh system for RBCs
You either have a D protein or not.
If you have the D protein, you are Rh +
If you don’t have the D protein, you are Rh negative and have antibodies against D proteins. They can not receive Rh+ blood.
Universal donors
RBCs = O negative Plasma = AB positive
Note that plasma is always the complete opposite of RBC compatibility
Universal Recipients
RBCs = AB positive Plasma = O negative
Note that plasma is always the complete opposite of RBC compatibility
Type, screen, and cross
Typing = determining presence of ABO and Rh-D antigens (takes 5 min). Looks at surface proteins. Prevents 99.8% of transfusion reactions.
Screening = determining the presence of most clinically significant ANTIBODIES (takes about 45 min). This is looking for antibodies, not surface proteins.
Crossing = mixing blood with unit planned on being transfused (takes 45 minutes)
Emergency RBC transfusion from most to least desirable when you can’t get full T&S
1) Type specific partially crossmatched
2) Type specific uncross matched
3) O negative uncrossmatched
Pts with CAD should be transfused once Hct is around
28-30%
Hub value after acute blood loss
Will be the same as your initial. If you rapidly lose 1L of blood, the concentration in the blood stream is still the same, no time for fluid rebalancing yet (no hemodilution)
What does phosphate do in stored blood?
Buffer against acidosis.
RBCs do NOT have mitochondria. Therefore they rely on anaerobic metabolism to convert glucose to ATP – risk of acidosis!
Blood is stored at 1-6 degrees C to extend the lifespan of RBCs by slowing glycolysis
What does adenine do in stored blood?
Substrate for ATP synthesis
Hct of PRBCs
70%
How do PRBCs affect the dissociation curve?
Banked blood has lower levels of 2,3-DPG = shift to left, and impairs O2 unloading to the tissues.
Blood component processing
Leukoreduction = removing WBCs to prevent HLA aloimmunization
Washing = prevents anaphylaxis in IgA deficient patients
Irradiation = prevents graft vs. host disease
Most common diseases from blood transfusion
1) CMV
2) Hep B
3) Hep 3
4) HIV
In up to ___% of Hep C infections, it can cause cirrhosis, liver CA, failure and death
85%
Why do we give sodium bicarb in transfusion reactions?
Alkalinizes the urine to reduce Hgb precipitation in the tubules.
WE also give fluid bolus to help wash the Hgb out of the tubules.
S/S of acute hemolytic transfusion reaction
Observed under anesthesia:
1) Hemoglobinuria (usually the presenting sign!!!)
2) Hypotension
3) Increased surgical bleeding
Masked by anesthesia:
- fever
- chills
- chest pain
- dyspnea
- nausea
- flushing
How does DIC start from a transfusion reaction?
Erythrocyin is released from RBCs and activates the intrinsic cascade!
Leads to uncontrolled fibrin formation and uses all the body’s platelets, and factors 1, 2, 5, and 7
Treatment of acute hemolytic transfusion reaction
- stop the transfusion
- Keep UO > 75-100mL/hr with IVF, mannitol, or lasix (if mannitol doesn’t work)
- Give Na Bicarb to alkalinize the urine
- Send urine and plasma hub samples to the blood bank
- Check plts, PT, and fibrinogen to look for DIC
- Send any unused blood to the blood bank to double check for cross match
- Support BP with IVF and pressers as needed
What is better, salvaged (cell saver) or banked blood?
Salvaged blood. Has higher levels of 2,3-DPG and ATP and are better able to keep their biconcave shape
Cell saver contraindications
- Oncological procedures (CA procedures)
- Infected surgical site
- Sickle cell disease
- Thalassemia
- Topical drugs in the surgical field (butadiene, chlorhexidine, topical antibiotics, chemo, etc)
Why is cell saver controversial in c-seciton?
Risk of amniotic fluid embolism (anaphylactoid syndrome of pregnancy)
