Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
53 Cards in this Set
- Front
- Back
|
What is "PT"? What does it measure? |
Prothrombin Time: - Tests extrinsic coagulation pathway |
|
|
What is "PTT"? What does it measure? |
Partial Thromboplastin Time: - Tests intrinsic coagulation pathway |
|
|
What is "INR"? What does it measure? |
International Normalized Ratio - Reports PT results |
|
|
What is in PRBCs? Amount? |
1U = ~300 mL (+/- 50 mL)
No platelets or clotting factors, can be mixed with NS to infuse faster |
|
|
What do "platelets" replace? |
Replaces platelets with units of platelets (6-10 units from single donor or random donors) |
|
|
What does FFP replace? |
Replaces clotting factors (no RBCs/WBCs/platelets) |
|
|
What does cryoprecipitate (cryo) replace? |
Replaces fibrinogen, von Willebrand factor, and some clotting factors |
|
|
Which electrolyte is most likely to fall with infusion of stored blood? Why? |
Ionized calcium; the citrate preservative used for storage of blood binds serum calcium |
|
|
What changes occur in the storage of PRBCs? |
- Decreases Ca2+ - Increases K+ - Decreases 2,3-DPG - Increases H+ (decreases pH) - Decreases PMNs |
|
|
What are general guidelines/indications for blood transfusions? |
- Acute blood loss, Hgb <10, and history of CAD/COPD OR - Healthy symptomatic pt with Hgb <7 |
|
|
What is the rough formula for convering 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 |
|
|
What blood type is the universal donor for FFP? |
AB |
|
|
What is a type and screen? |
Pt'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? |
Pt's blood is sent to the blood bank and cross-matched for specific donor units for possible blood transfusion |
|
|
Define thrombocytopenia? |
Low platelet count <100,000 |
|
|
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 med causes platelets to irreversibly malfunction? |
Aspirin (inhibits cyclooxygenase) |
|
|
What is Plavix |
Clopidogrel - irreversibly inhibits platelet P2Y(12)-ADP receptor (blocks fibrin cross-linking of platelets) |
|
|
What platelet count is associated with spontaneous bleeding? |
<20,000 |
|
|
What should the platelet count be before surgery? |
>50,000 |
|
|
When should "prophylactic" platelet transfusions be given? |
With platelets <10,000 (old recommendation was 20,000) |
|
|
What is microcytic anemia "until proven otherwise" in a man or post-menopausal woman? |
Colon cancer |
|
|
Why not infuse PRBCs with lactated ringers? |
Calcium in LR may result in coagulation within the IV line (use NS) |
|
|
For how long can PRBCs be stored? |
About 6 weeks (42 days) |
|
|
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 in 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 (Lasix) to protect kidneys, alkalinize urine (bicarb), and 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 pre-op? |
At 1 week, because platelets live 7 to 10 days (must use judgment if pt is at risk for stroke or MI; it may be better to continue and use excellent surgical hemostasis in these patients) |
|
|
What can move the oxyhemoglobin dissociation curve to the right? Implications? |
- Acidosis - 2,3-DPG - Fever - Elevated PCO2 (to the right means greater ability to release O2 to tissues) |
|
|
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 (8 sounds like A) |
|
|
What is the pre-op treatment of hemophilia A? |
Factor VIII infusion to >100% normal preop levels |
|
|
What coag study is elevated in hemophilia A? |
PTT (there are two major hemophilias and two t's in PTT) |
|
|
What factor is deficient in hemophilia B? |
Factor IX |
|
|
How do you remember which factors are deficient in hemophilia A and B? |
Alphabetically and chronologically: - Hemophilia A = Factor VIII - Hemophilia B = Factor IX |
|
|
How are hemophilias A and B inherited? |
X-linked recessive |
|
|
What is von Willebrand's disease? |
Deficiency of von Willebrand factor (vWF) and factor VIII:C |
|
|
How is von Willebrand's disease inherited? |
Autosomal dominant |
|
|
What is used to correct von Willebrand's disease? |
DDAVP (desmopressin) or cryoprecipitate (fibrinogen, vWF, some clotting factors) |
|
|
What coagulation test is abnormal in Hemophilia A, B, and vWF? |
- Hemophilia A: PTT (elevated) - Hemophilia B: PTT (elevated) - von Willebrand's disease: bleeding time |
|
|
What is the effect on the coagulation system if the patient has a deficiency in protein C, protein S, or anti-thrombin III? |
Hypercoagulable state |
|
|
What is a "left shift" on a CBC? |
Juvenile polymorphonuclear leukocytes (bands)
(Legend has it that the old counters for all the blood cells had the lever for bands on the LEFT of the counter) |
|
|
What is the usual "therapeutic" INR? |
With coumadin, usually shoot for INR of 2-3 |
|
|
What is the most common inherited hypercoagulable state? |
Factor V Leiden (think LEiden = LEader) |
|
|
What is Xigris? Indication? |
Activated protein C, which is used in severe sepsis |
