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74 Cards in this Set
- Front
- Back
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How long does a type and screen take vs a type and cross?
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-screen - 5 min
-cross - 45 min |
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What routine tests are done on donor blood?
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1. HbAg
2. Syphillis 3. HIV 4. ALT - marker for presence of hepatitis non A, non B |
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In a blood bank, how is red cell survival measured?
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On the basis of 70% RBC survival 24 hrs after transfusion
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Does Rh status matter when giving platelets?
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Yes, only in life threatening instances should platelets from a Rh+ donor be given to a Rh- recipient
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Does ABO status matter when giving platelets?
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ABO compatible platelets are no better than incompatible platelets in terms of hemostasis but they probably last longer and should be used if possible.
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Is Rh status important when giving FFP or cryo?
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No bc there are no red blood cells in FFP or cryo
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What are the 4 types of blood transfusion reactions?
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1. Urticarial-Pruritic reaction
2. Febrile non-hemolytic reaction 3. Febrile hemolytic reaction 4. Anaphylactic reaction |
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Within what time must washed RBCs be administered?
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-If stored at 20 degrees C - 6 hrs
- Stored at 1-6 degrees C - 24 hrs |
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What are the risks associated with giving FFP?
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1. Hepatitis
2. AIDS 3. allergic reaction to foreign particles |
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If a pt is bleeding at the end of surgery in which many units of blood have been transfused what do you do?
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1. Determine if a coagulopathy exists based upon lab values
2. If so, admin FFP and/or platelets |
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How fast must blood be given to see cardiovascular changes with ACD blood?
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If average adult size - 1 unit/5 min
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How depleted must factors be to see spontaneous bleeding? Oozing from surgical wound?
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- spont bleeding: 10-20% factor range
- oozing - 20-30% factor range |
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What are the causes of intraop coagulopathies, ie unexplained bleeding?
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1. DIC
2. Dilutional thrombocytopenia 3. Low factors 4. Hemolytic transfusion reactions |
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In the setting of clinical bleeding, where should you maintain platelets?
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in the range 50,000-75,000
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What is the minimal safe level of Hg?
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- the 10 gm hemoglobin rule is unnecessarily restrictive
- O2 delivery varies little between Hct of 20-50% - Assuming a normal intravascular volume, a healthy pt can tolerate a Hct of 20% |
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What are the alternatives for pts who refuse blood transfusions?
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1. Autologous blood
2. Cell Saver 3. Acute normovolemic hemodilution 4. Fluosol-DA |
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What is the estimated blood volume of the following age groups?
Preterm newborn Term newborn Infants 1 mo - 12 months Children 1-3 y/o 4-6 y/o 7-18 y/o Adults |
Preterm newborn - 100 cc/kg
Term newborn - 85 cc/kg Infants 1 mo - 12 months - 80 cc/kg Children 1-3 y/o - 75-80 cc/kg 4-6 y/o - 80-85 cc/kg 7-18 y/o - 85-90 cc/kg Adults 70-75 cc/kg |
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What is the equation to determine maximum allowable blood loss?
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ABL = EBV x (starting Hct - final Hct/starting Hct)
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What is the volume of PRBCs necessary to achieve a desired Hct?
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-Useful rule of thumb is that 10 cc/kg PRBCs increases Hct 1%
More precisely: Vol to infuse = EBV x (target Hct-starting Hct) / (donor Hct - target Hct) - donor Hct usually 55-70% (avg 60%) - infusion rate is 5-10 cc/min - formula is specific to pediatrics |
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What antigen is on the cell membrane of the following blood types? What antibody will it react with?
A B AB O |
A = A antigen which will react with the anti-A antibody
B = B antigen which will react with the anti-B antibody AB = AB antigen which will react with both the anti-A and anti-B antibody 0 = has no antigens and does not react with either anti-A or anti-B antibodies |
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In a pt's serum, there are naturally occurring....
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Antibodies directed at the missing antigen
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What antibodies does a pt's serum contain with the following blood types?
A B AB O |
A = antibody to B antigen
B = antibody to A antigen AB = no antibodies O = antibodies to A and B antigens |
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If donor PRBCs are O, A, B, or AB, list what the plasma of the recipient can be for each. (ie what blood types can use the donor PRBCs)
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O = O, A, B, AB (ie universal donor)
A = A, AB B = B, AB AB = AB |
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If donor PRBCs are O, the plasma of the recipient can be...
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O = antibodies to both A and B antigen are present in O serum. There are no A or B antigens on O so O serum is acceptable.
A = antibodies to B antigen present in A serum. There are no B antigens on O cells so A serum is acceptable B = antibodies to A antigen are present in B serum. There are no A antigens on O cells so B serum is acceptable. AB = there are no antibodies to A or B antigens in AB serum. Their are neither on O cells so AB serum is acceptable |
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If donor PRBCs are A, the plasma of the recipient can be...
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A and AB
A = antibodoes to B antigen are present in A serum. With donor A cells, we dont' fear B antibodies. A serum is acceptable in the setting of A donor AB = There are no antibodies to A or B antigens in AB serum. Donor PRBCs with A antigen will not present a problem to AB serum. O = There are A and B antibodies in O serum. Antibodies to A will cause lysis. B = There are A antibodies in B serum. A antibodies will react with A antigen on A cells to cause lysis |
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If donor PRBCs are B, the plasma of the recipient can be...
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B and AB
B = has antibodies to A. With B cells A antibodies are not a problem AB = No antibodies to A or B antigens in AB serum. Donor B cells will not be a problem O = There are A and B antibodies in O serum. Antibodies to B will cause lysis A = B antibodies in A serum. These will bind B antigens on B cells and cause lysis |
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If donor PRBCs are AB, the plasma of the recipient can be...
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AB only
AB = no antibodies in AB serum to react with A and B antigens so it is acceptable O = there are both A and B antigens in O serum. These will bind A and B antigens on AB cells and cause lysis A = B antibodies in A serum. These will bind B antigens on AB cells and cause lysis B = A antibodies in B serum. Will bind A antigens on AB cells and cause lysis. |
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When should one not be switched back to the pts blood type after being transfused with uncrossmatched?
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After the admin of 2 units of Group O WHOLE blood
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Can an AB- patient safely receive O- plasma?
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NO
-AB pt has A and B antigens and no antibodies. -O pt has no antigens and antibodies to A and B in the serum -These antibodies would lyse AB blood. -Plasma from AB would be acceptable |
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Aspirin MOA
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Irreversible COX-1 inhibitor
-COX-1 catalyzes the conversion of arachidonic acid to prostaglandins which promotes platelet aggregation |
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What is GP IIb/IIIa?
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An aggregation receptor and inhibition of this receptor inhibits platelet aggregation
-these receptors allow fibrinogen to form a bridge between platelets, triggering platelet aggregation -GP IIb/IIIa inhibitors inhibit such aggregation by blocking ADP binding to the IIb/IIIa receptor |
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What are the IV and oral GP IIb/IIIa inhibitors?
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- IV (reversible) - Abciximab, Eptifibatide, Tirofaban
- PO (irreversible) - Ticlid, Plavix - irreversibly block ADP on the receptor preventing this activation and hendering the GP IIb/IIIa receptor |
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What is the mechanism for the development of a coagulapathy following massive tranfusion?
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1. Dilutional thrombocytopenia (more likely)
2. Dilution of plasma concentrations of factors 5 and 8 |
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When is dilutional thrombocytopenia seen?
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After >10 units of whole blood bc there are essentially no viable platelets in blood stored at 4 deg C for >24hrs.
-If >10 units are administered, platelet count can be <100,000 |
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What happens to factor 5 and 8 in whole blood when stored?
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Concentration decreases to 20-50% of normal after 21 days of storage.
-20% of factor 5 and 30% of factor 8 are necessary for surgical hemostasis |
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How much blood is needed to cause an acute hemolytic transfusion reaction?
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As little as 50cc of blood bc this is the amount that typically exceeds the haptoglobin binding capacity
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What tests are used to diagnose an acute hemolytic transfusion reaction?
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1. plasma free hemoglobin
2. antiglobulin (detects antibodies on RBCs) 3. PT and PTT 4. fibrinogen |
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Why is protamine highly basic?
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Bc of its high arginine content
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What is the recommended rate of protamine infusion?
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50 mg per 10 min or no faster than 20 mg per min
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How fast should citrated blood be infused?
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Infusion of 50 cc/ 70 kg/ min is ok bc it has little effect on Ca levels
- If increased to 150 cc/ 70 kg/ min, the ionized Ca level can drop from 1.1 to 0.65 |
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Are pediatric pts more susceptible to hypocalcemia following transfusion? Why or why not?
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Yes bc they have a decreased ability to metabolize citrate and to mobile calcium stores
-Especially a problem with FFP vs PRBC bc FFP contains more citrate per unit -Peds pts may require CaCl2 (2.5-5 mg/kg) or Ca gluconate (7.5-15 mg/kg) during rapid transfusion |
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What other co-existing factors may increase the tendency to hypocalcemia during rapid transfusion?
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1. hyperventilation which causes a decrease in Ca levels due to an alkalosis induced increase in binding of Ca by proteins
2. hypothermia 3. liver disease |
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Manifestation of hypocalcemia in an awake pt
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1. numbness
2. circumoral paresthesias 3. confusion and seizures 4. clumsiness 5. stridor 6. tetany 7. Chvosteks or Trousseaus sign 8. weakness or fatigue |
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Manifestations of hypocalcemia in the anesthetized pt
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1. hypotension
2. increased LV filling pressures or CVP 3. narrowed pulse pressure 4. prolonged QT interval (not consistent or reliable) |
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What is FFP?
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The liquid portion of a single unit of whole blood separated from RBCs within 6 hrs and frozen
-Can be stored at -18 deggres C for 1 year and is good for 6 hrs after thawing |
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Platelet count in primary vs secondary polycythemia
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Primary - platelets elevated
Secondary - not elevated |
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What is polycythemia? What are the 2 types?
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An overproduction of red blood cells
- Primary polycythemia - disorder arises at the level of the hematopoietic stem cells - Secondary polycythemia - overproduction caused by the increased stimulation of the bone marrow by EPO |
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Describe the hemoglobin levels found in polycythemia
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Hgb levels >20 is unequivolcally associated with increased red cell mass
- values between 18-20 could be caused by a decreased plasma volume and not by an increase in red cell mass |
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What are the signs and symptoms of primary polycythemia AKA polycythemia vera?
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1. increased platelet count and WBC
2. splenomegaly 3. severe itchign following hot showers or baths 4. EPO level is in the normal or low normal range |
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What is erythropoietin?
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A glycosylated protein that is synthesized in resonse to hypoxia, mainly by the peritubular capillary endothelial cells of the reanl cortex by means of an oxygen sensing mechanism
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What are the most common causes of hypoxic polycythemia?
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Cardiovascular defects involving right to left shunts and pulmonary dz interfering with proper oxygenation
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What are the clinical findings associated with hypoxic polycythemia?
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1. cyanosis
2. hyperemia of the sclera and mucous membranes 3. clubbing of the fingers |
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What is the treatment for polycythemia?
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phlebotomy when the Hct rises > 65%, as well as when HAs and htn occur due to hyperviscosity
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How does living at high altitudes effect hemoglobin?
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Living at high altitudes causes hypoxic polycythemia
- Hgb levels increase 4% for each rise of 1000 M in altitude |
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What drugs can prolong bleeding time?
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1. ASA
2. NSAIDs 3. Nitroglycerin (makes bleeding time inaccurate due to vasodilation and increasing capacitance 4. Dextran - doses >1500 cc, may not appear until 6-7hrs after the infusion 5. chemotherapeutic drugs |
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What is the most common coagulation defect in the setting of renal failure?
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Decreased platelet adhesiveness
-accumulation of metabolic acids may interfere with factor 8 activity -usually with plasma Cr >6 |
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AT-III normally function by neutralizing which activated clotting factors?
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2, 10, 11, 12, 13
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How long can CPD vs CPDA-1 blood be stored?
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CPD - 21 days
CPDA-1 - 35 days (adenine provides substrate for the synthesis of ATP |
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How do you treat the following deficiencies?
I (fibrinogen) II (prothrombin) V VIII von Willebrands IX Platelets |
I (fibrinogen) - Cryo or fibrinogen (inc to >50 mg/dl)
II (prothrombin) - FFP V - FFP (inc to 5-20%) VIII - Cryo or factor 8 concentrate (keep levels >30%) von Willebrands - Cryo IX - specific concentrates (keep >30%) Platelets - platelets |
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What are indications for platelets?
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1. thrombocytopenia associated with clinical coagulopathy
2. clincial coagulopathy from platelet dysfunction not thrombocytopenia (CABG, ASA, uremia, Glanzmann's thrombasthenia) |
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During coagulopathy what should ou use first, platelets or FFP?
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Platelets bc dilutional thrombocytopenia or platelet dysfunctionproduces a coagulopathy well before clinically significant plasma coagulation deficiency
- Additionally 4-6 units of platelet concentrate contains the same factor content as one unit of FFP |
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What are the physical signs of vWD?
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1. epistaxis
2. bleeding from mucosal surfaces 3. easy bruising |
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One unit of whole blood yields how much PRBCs after being centrifuged?
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250 mL with a HCT of 70% and following the addition of saline preservatives volume reaches 350mLs
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What are the components of FFP?
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1 unit/mL of all pro coagulants and 3-4 mg/cc fibrinogen
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What are the components of cryoprecipitate?
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Fibrinogen 250 mg, fibronectin, vWF, factor 8 (80-145 units, factor 13
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The supernatant of centrifuged whole blood is centrifuged to yield...
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Platelets and plasma
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The unit of platelets obtained usually contains how much plasma?
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50-70 mLs
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How is plasma obtained?
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Remaining plasma supernatant is further processed and frozen to yield FFP
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How is FFP processed?
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It is rapidly frozen to help prevent inactivation of labor factors 5 and 8
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How is cryo made?
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By the slow thawing of FFP
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What does cryo contain?
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High concentrations of factor 8 and fibrinogen.
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How much plasma does one unit of blood yield?
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200 mLs
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How much does one unit of FFP increase the level of each clotting factor? What is the initial therapeutic dose?
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2-3%; 10-15 cc/kg
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How long do transfused platelets generally survive?
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1-7 days
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