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41 Cards in this Set
- Front
- Back
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What is the most commonly used blood product?
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RBC
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What is the hematocrit of RBC?
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60%
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What is the formula for calculating the blood volume of an adult?
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weight (kg) * 70mL/kg
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What is the formula for blood volume for newborns and why is it different from adults?
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weight (kg) * 100mL/kg
It's different because babies have little fatty tissue and are more vascular. |
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When is the only time that babies are given an entire unit of blood? What is the volume that is given?
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When they are being "exchange transfused" bc the mother is producing an antibody that is causing hemolysis in the baby.
The volume that's given is 10-15mL/kg. |
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What is cryoprecipitate and what does it contain?
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Cryoprecipitate is the thawed precipitate of FFP (needs to be centrifuged out). It contains fibrinogen (F2), fibronectin (made in hepatocytes), WF, F8, and F13. Remember that vWF and F8 lways go togehter.
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How much is one unit of cryoprecipitate? In what situations is cryoprecipitate used and how much is given?
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One unit (from one unit of FFP) is 15 mL. 10 units are given to patients with acute liver failure or in DIC where fibrinogen is low.
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What types of platelet donations are there?
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2 types:
1) Random donor platelets where 6-8 units of whole lood must be collected from different patients to get 1 unit of platelets 2) Apheresis platelets - Platelets are collected separately from whole blood and one donor can supply 1 unit. Random donor platelets are cheaper to use but apheresis platelets are safer. |
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What type of platelet donation is performed at UAB?
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Apheresis platelets - safer to use
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In what situations is apheresis platelets given?
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thrombocytopenia, chemotherapy/bone marrow probelms, immunosuppressed like with organ transplants
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How long are platelets stored?
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5 days. Platelets are active for 7 days but only kept for 5 days now because they're kept at room temperature. There are also concerns of contamination.
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Do platelets have to be ABO compatible and why?
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Yes, because they're suspended in plasma.
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What types of concentrated forms of Factors 8 and 9 are there? How safe are they?
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1) Plasma derived factors administered IV and given to people who've been exposed to blood products
2) Recombinant factors - even purer and safer. Reserved for PUPs (previously untreated patients) like hemophiliac babies. These forms are pretty safe - no one's contracted infection from these. |
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Who receives concentrated forms of Factors 8 and 9?
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hemophiliacs. Don't given them croprecipitates. Instead, they get like 392 units of Factor 8 (Type 1 hemophiliac). Also vWF disease, bc there is concentrate of F8, F9, and vWF
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What's the first fluid source that you gien someone who's losing massive amounts of blood volume?
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Given saline and ringers solution and colloids to expand her volume and help out with her hypotension.
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When do you give someone blood?
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Blood loss is hemodynamically significant at 15% blood loss. For example, if someone weights 70kg, she has 70kg(70mL)=5L of total blood volume. 15% is 750mL.
You don't need to wait on Hct and HB numbers to give them whole blood. These numbers weill probably be okay because the concentration per unit volume will be the same. |
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What type of blood do you give someone if the lab results haven't come back yet?
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Type O negative packed RBCs because there are no antigens on the surface. If the O on the surface of a bag is solid, it's O positive. There's very little plasma in packed RBCs. It's resuspended in AS3 (anticoagulant-preservative and additive solutions). There are no platelets or clotting factors in PRBCs.
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What tests do you give someone before treating them?
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1) Forward type screening, with patient RBCs and different reageant serums, to see what antigens are on the patient's cell surfaces
2) Reverse type screening, with patient's serum and different reagent RBCs, to see what antibodies are in the patient's serum |
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What blood components may be different because a patient is female?
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1) Baseline HCt and Hb values may be lower.
2) If she was pregnant in the past, she may have Rh antibodies. Also if she's Rh negative and you give her Rh positive blood, then she has a 50% chance per unit of developing Rh antibodies. |
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What percent of women are Rh negative?
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15%
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Are women given Rh positive or Rh negative blood?
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Rh negative because if she is Rh negative (15% of women), she has a 50% chance per unit of developing anti-D antibodies (anti-Rh factor antibodies). This could cause miscarriages later on.
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What kinds of infection does a splenic laceration cause an increased risk of?
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encapsulated organisms like pneumococcus, meningococcus, haemophilus
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What happens if you given a patient who's been exposed to the D antigen (Rh factor) some R positive blood?
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Regardless of sex, they have a reaction bc antibodies have been formed once before.
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Are males given Rh positive or Rh negative blood?
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Rh positive.
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What are the side effects of transfusing only PRBCs?
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Because there are no platelets or clotting factors, there aren't really any problems. Massive transfusion (10 units in 24 hours) can cause a problem, with
1) dilution of clotting factors and platelets 2) hyperkalemia 3) hypomagnesemia 4) citrate toxicity leading to hypocalcemia 5) hypothermia - PRBCs are stored in the fridge |
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What tests do you run on a patient to see if they're hemodynamically stable and after a transfusion?
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1) CBC - gives Hct, platelet count, white count, Hb
2) PT/PTT - gives factor dilution. Probably prolonged, with multiple factor deficiencies. PT is normally 12-14 seconds. |
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Is an INR needed to see if they're hemodynamically stable?
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No. INR is not needed to assess bleeding time - it's only used to assess warfarin treatment.
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If PT and PTT are prolonged, what blood products do you give?
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1) plasma (FFP) - has all coagulaton factors. Use Type AB+ for plasma if you don't know the patient's blood type, because there are no antibodies.
2) Platelets - The plasma that they're in is what matters, so AB+ is also the best option. Type A is the 2nd best option because anti-B antibodies aren't as strong as anti-A. |
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What test neds to be done prior to issuing PRBCs once you know a patient's blood type? So you're no longer in an acute setting?
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1) Crossmatching - Mix the donated blood with the patient's blood and see what happens. The patinet could have over 400 antibodies to other antigens, espeically people who've been transfused before or been pregnant. A reaction can cause a hemolytic transfusion reaction or hemolytic disease of a newborn. Only 20-25 of the 400 are clinically signifcant, and the immunogenicity of the antigens is variable. The D antigen produces an immunogenic effect 50% of the time and is the most potent. Kell is the 2nd most potent and is only 3% immunogenic - you'd produce antibodies only 3% of the time.
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What's the difference between a Type & Screen and a Type & Crossmatch?
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1) Type & Screen - Patient's serum and other RBCs: Types are the Forward and Reverse types. Screen incubates the patient's serums with 3 different O type cells to see if there's agglutination and immunogenicity.
S for serum! 2) Type & Crossmatch - Blood and blood: Mix the patient's blood with the donor's blood. Check for agglutination and immunogenicity. |
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What's the point of type and screens?
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Just because the blood is the same type doesn't mean there's a match.
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What are the symptoms of a hemolytic tranfusion reaction?
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dark urine, fever, ypotension, pain/itching at transfusion site, flank pain, chest pain, feeling of impending doom
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What can reduce the chances of a febrile transfusion reaction occurring?
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Leukoreduction, which removes WBCs from the blood product
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What may be te first indication of hemolysis between pre and 15-minute measurements?
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Fever. Always stop the transfusion immediately with 2degrees F or 1degree C increase in temperature, in case of hemolytic transfusion reactions.
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What is the most common cause of a hemolytic transfusion reaction?
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Mislabeling of blood! Another cause is not nowing the results of the antibody screen, so antibodies to one of 400 other antigens. The reaction wouldnt be as dramatic as if due to anti-A or anti-B
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Why do you start slowly when transfusing?
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Activatio of complement cascade can lead to DIC and renal failure
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What is the mechanism of action of anti-A and anti-B antibodies?
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Activates IgM (the worst antibody!) because it binds complement very efficiently, leading to intravascular hemorrhage (acute hemolytic reaction)
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What is the mechanism of action of anti-D antibodies?
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Activates IgG, which doesn't activate complement as strongly. Causes extravascular hemolysis.
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What other tests are done?
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1) Transfusion work up: Confirm blood type, repeat BO typing, hemolysis test (DAT or Coombs)
2) If there was a transfusion reaction, then the patient's cells are coated with antibodies (either IgG or IgM), and you need to separate, wash, Coombs test, elute antibodies, and check what antibodies are binding to 3) Check te color of the plasma, which will be darker with hemolysis 4) Urine test for bloodto see if there is free Hb due to hemolysis 5) Check for other antigens that can cause problems, like D, C, c, E, e, Kell, Duffy a, Duffy b, Jka, Jkb |
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What risks can blood transfusions have?
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1) Infectiou - Hep C and HIV (1 in a million risk), HepB, bacterial contamination (due to platelets)
2) Mistransfusion, TRALI, GVH, TACO (transfusion related circulatory), under-transfusion |
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Why do patients of die from TRALI?
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Because a prolonged INR is believed that a patient is going to bleed. WHAT?
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