Blood & Blood Products Flashcards
What is PT?
Prothrombin Time:
Tests extrinsic coagulation pathway
What is PTT?
Partial Thromboplastin Time:
Tests intrinsic coagulation pathway
What is INR?
International Normalized Ratio:
Reports PT results
What are packed RBCs?
One unit equals 300 mL.
No platelets or clotting factors, can be mixed with NS to infuse faster.
What is FFP?
Fresh Frozen Plasma:
Replaces clotting factors (no RBCs, WBCs, or platelets)
What is cryoprecipitate?
Replaces fibrinogen, von Willebrand factor, and some clotting factors
Which electrolyte is most likely to fall with the infusion of stored blood? Why?
Ionized calcium.
The citrate preservative used for the storage of blood binds serum calcium.
What changes occur in the storage of PRBCs?
Decreased Ca, 2,3-DPG, pH, PMNs.
Increased K, H.
What are general guidelines for blood transfusion?
Acute blood loss, Hgb
What is the rough formula for converting Hgb to Hct?
Hgb X 3 = Hct
One unit of PRBC increases Hct by how much?
3-4%
Which blood type is the universal donor for PRBCs?
O negative
Which blood type is the universal donor for FFP?
AB
What is a type and screen?
Patient’s blood type is determined and the blood is screened for antibodies.
A type and cross from that sample can then be ordered if needed later.
What is a type and cross?
Patient’s blood is sent to the blood bank and cross-matched for specific donor units for possible blood transfusion
What is thrombocytopenia?
Low platelet count (
What are the common causes of thrombocytopenia in the surgical patient?
Sepsis, H2 blockers, heparin, massive transfusion, DIC, antibiotics, spurious lab value, Swann-Ganz catheter
What can be given to help correct platelet dysfunction from uremia, aspirin, or bypass?
DDAVP (desmopressin)
What common medication causes platelets to irreversibly malfunction?
Aspirin
What is Plavix?
Clopidogrel:
Irreversibly inhibits platelet P2Y12 ADP receptor (block fibrin cross-linking of platelets)
What platelet count is associated with spontaneous bleeding?
What should the platelet count be before surgery?
> 50,000
When should prophylactic platelet transfusion be given?
With platelets
What is microcytic anemia, until proven otherwise, in a man or postmenopausal woman?
Colon cancer
Why not infuse PRBCs with lactated Ringer’s?
Calcium in LR may result in coagulation within the IV line
For how long can PRBCs be stored?
About 6 weeks
What is the most common cause of transfusion hemolysis?
ABO incompatibility as a result of clerical error
What is the risk of receiving a unit of blood infected with HIV?
1/1,000,000
What are the symptoms of a transfusion reaction?
Fever, chills, nausea, hypotension, lumbar pain, chest pain, abnormal bleeding
What is the treatment for transfusion hemolysis?
Stop transfusion; provide fluids; perform diuresis to protect kidneys; alkalinize urine; give pressors as needed
What component of the blood transfusion can cause a fever?
WBCs
What is the transfusion trigger Hct in young healthy patients?
21%
What is the widely considered optimal Hct in a patient with a history of heart disease or stroke?
30%
When should aspirin administration be discontinued preoperatively?
At 1 week because platelets live 7-10 days
What can move the oxyhemoglobin dissociation curve to the right?
Acidosis, 2,3-DPG, fever, elevated PCO2,
What is the normal life of RBCs?
120 days
What is the normal life of platelets?
7-10 days
What factor is deficient in hemophilia A?
Factor VIII
How can the clotting factor for hemophilia A be remembered?
Eight sounds like A
What is the preoperative treatment of hemophilia A?
Factor VIII infusion to 100% normal preoperative levels
What coagulation study is elevated with hemophilia A?
PTT
How do you remember which coagulation study is affected by the hemophilias?
There are 2 major hemophilias and 2 T’s in PTT
What factor is deficient in hemophilia B?
Factor IX
How are hemophilias A and B inherited?
X-linked recessive
What is von Willenbrand disease?
Deficiency of von Willenbrand factor (vWF) and factor VIII:C
How is von Willenbrand disease inherited?
AD
What is used to correct von Willenbrand disease?
DDAVP or cryoprecipitate
What coagulation study is elevated in von Willenbrand disease?
Bleeding time
What is the effect on the coagulation system if the patient has a deficiency in protein C, protein S, or antithrombin III?
A hypercoagulable state
What is a left shift on a CBC?
Juvenile polymorphonuclear leukocytes (bands).
What is the usual therapeutic PT?
With coumadin, usually shoot for an INR of 2.0-3.0
What is the acronym basis for the word “Warfarin”?
Wisconsin Alumni Research Foundation - ARIN
What is the most common inherited hypercoagulable state?
Factor V Leiden
What is Xigris?
Activated protein C, which is used in severe sepsis
