Physiology-Transfusion Medicine Flashcards
What are ways we type blood?
Forward typing (does your blood react with an externally applied antibody) and Reverse typing (do antibodies in your blood react with an external antigen)
What are you if your blood reacts with anti-B and anti-D antigens in forward typing?
You are B and Rh+ = A+
What red cells can you get if you are O? A? B? AB? What happens if you give the wrong type?
If you give blood to someone that has IgM antibodies for that blood type, IgM antibodies will fix complement to the RBCs and cause intravascular hemolysis, DIC or renal failure.
You find out that a patient received the wrong blood type after a transfusion. What do you do?
Keep IV line open and give IV fluids, aggressive diuresis w/Lasix or mannitol and check labs for intravascular hemolysis (bili, LDH, haptoglobin, Hgb, Hct and urine Hgb)
What is the difference between a type and screen and a type and cross?
T + S: after determining ABO and Rh type, you screen the plasma for antibodies to Rh, Kell, Duffy antigens by mixing the patients plasma with reagent blood cells with these known antigens to see if there is clumping. T + C: after doing T + S, you mix the donor blood with the recipient blood to see if there is any clumping.
How long will blood be held for if you do a type and cross?
72 hours
When do you order a type and screen?
When there is < 50% chance the patient will need blood products of any kind. Note that this does not reserve any blood in the blood bank.
When do you order a type and cross?
When there is > 50% chancre the patient will need a red cell transfusion. This reserves units in the blood bank.
When do you order a transfusion?
When it is time for the patient to actually receive the blood.
How do you order fresh frozen plasma?
By whole units, FFP must be ABO compatable
How do you order platelets?
By APT, platelets are typically transfused just one platelet at a type without regard to ABO blood type.
How do you order cryoprecipitate and what is it?
By 10-pack units, it is a plasma-derivative containing fibrinogen, VIII, XIII, vWF and fibronectin.
How much do you expect a healthy person’s Hgb and Hct to change that receives one unit of PRBCs? Who does this rule not apply to?
1 unit of PRBCs = increase in Hgb by 1g/dL and Hct by 3%. This does nota poly to people who are bleeding or getting significant IVF.
What happens to a patient’s INR who is on a high therapeutic dose of coumadin and you give FFP?
It will bring the INR down from 8-10 near 2.5, but not much better than that. FFP is most effective in stopping bleeding, not so much in lab values.
How much would you expect platelet count to change after giving 1 unit APT? Who does this not apply to?
Raise platelet count by 30,000. This does not apply to people actively bleeding.
