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;
63 Cards in this Set
- Front
- Back
What are the indications for urokinase therapy? |
1. PE |
|
What should you give a patient requiring urgent surgery to reverse the effects of urokinase? |
1. whole blood, |
|
What is the mechanism of urokinase and where is it produced? |
produced in the kidney and found in the urine, converts plasminogen to plasmin which degrades clots and increases fibrin degradation products |
|
What does a decreased retic count imply? |
inability to synthetize RBCs |
|
When do you see an isolated prolonged PTT? |
hemophilia A, B and von Willebrands disease |
|
When do you see isolated prolonged PT? |
vit K deficiency |
|
When do you see both PT and PTT prolonged? |
coumadin, |
|
What are causes of inhibited platelet fxn? |
aspirin - irreversibly acetaylates COX |
|
How much platelets are lost after transfusion of one blood volume? |
60-65%, if two blood volumes are transfused than 85% of platelets will be lost |
|
What are causes of thrombocytopenia? |
"The platelets HID" |
|
What is the minimum platelet count required for surgery? |
>50,000 |
|
How long do platelets survive? |
about 10 days |
|
What are the three components of coagulation? |
1. vascular component (responsible for vasoconstriction), |
|
What is the normal PT and PTT? |
PT 12-14s, |
|
Where is factor VIII synthetised? |
reticuloendothelial system |
|
What are the Vit K dependent factors? Why is vitamin K necessary? |
2, 7, 9, and 10 |
|
What factors are shared by both the extrinsic and intrinsic pathways? |
7, 9, and 12 |
|
What is the procoagulant problem with von Willebrand disease? |
lack of protein important for function of factor 8 as well as platelet fxn |
|
How is hemophilia A and hemophilia B treated? |
A - factor 8 concentrate; |
|
what tests are abnormal in vWD? |
PTT (due to decreased factor 8) |
|
What is the treatment of vWD? |
- best treatment is humate-P (factor VIII concentrates) or DDAVP, |
|
When can you consider regional anesthesia in patients with vWD? |
when the level of the factors is clearly above 30% |
|
What is the mechanism of DDAVP in vWD? |
temporarily increases various moieties of the factor VIII:vWF complex by causing their release from endothelial cells |
|
How do you choose between DDAVP and humate for treatment of vWD? |
- many hospitals do not have humate, |
|
Where is vitamin K synthetized? |
in the gut with the help of intestinal flora and then absorbed with the help of bile salts |
|
How long does parenteral vitamin K take to work? |
3-6 hrs |
|
What can cause a lack of vitamin K in the body? |
1. lack of production of vitamin K - malnutrition or antibiotic induced elimination of intestinal flora, |
|
How does heparin work? |
- indirectly by means of a cofactor, |
|
what is the half life of heparin and how is it inactivated? |
1hr; |
|
How does protamine antagonize heparin? |
heparin is a strong acid and protamine is a strong base |
|
what is the appropriate dose of protamine to antagonize heparin? |
1mg protamine/100u heparin |
|
What can happen if too much protamine is given to reverse heparin? |
bleeding can worsen |
|
What are the 3 types of reactions to protamine? |
type 1-hypotension related to rapid drug administration; |
|
What is the best initial treatment for a severe protamine reaction? |
epinephrine followed by fluids |
|
what is the mechanism of tranexamic acid? |
competitive inhibitor of plasminogen activation, inhibiting the breakdown of clot (10x more potent than aminocaproic acid) |
|
What is the mechanism of urokinase? |
converts plasminogen to plasmin, plasmin then degrades clot increasing the amount of fibrin degradation products |
|
When is urokinase contraindicated? |
1. active internal bleeding, |
|
What is the mechanism of aprotinin? |
trypsin inhibitor which inhibits plasmins fibrinolytic activity |
|
What is determined with a type and screen? |
1. ABO and Rh status |
|
What is the risk of an adverse reaction after blood is type and screened? |
1:1,000 |
|
What does a type and crossmatch tell you and what is the risk of an adverse reaction? |
1. ABO and Rh, |
|
How is a type and cross done? |
Two parts: |
|
What is the normal red cell lifetime? |
120 days |
|
What is the normal half life of blood stored in CPD-A and ACD? |
- CPD-A: 35 days |
|
How much does one unit of platelets increase platelet count? |
10,000 |
|
What size filters should you use when giving blood? |
-macrofilters are sufficient (200 microns), |
|
What should you do if a patient has an urticarial rxn during a blood transfusion? |
This is among the MC transfusion reactions. |
|
What should you suspect if temperature rises 1 degree centigrade during a blood transfusion? How should you treat it? |
- febrile nonhemolytic reaction should be suspected |
|
What are signs of a febrile hemolytic transfusion reaction? |
- may occur following infusion of only a few cc's of blood with exhaustion of haptoglobin binding capacity and lysis of cells |
|
An anaphylactic reaction in a pt who has been previously transfused is most often due to what? |
IgA deficiency |
|
How do you treat blood transfusion reactions besides urticarial reactions? |
1. stop transfusion and support oxygenation, ventilation, and circulation (drugs i.e. epi) |
|
what are indications for leukocyte reduced RBCs? |
1. IgA deficient patients, |
|
What are leukocyte reduced RBCs? |
washing process removes 1. plasma proteins, 2. microaggregates, 3. platelets, and 4. leukocytes |
|
What blood should you give in emergency situations when a full cross match isn't practical (45min)? |
1. type specific partial cross match |
|
Why should you not dilute blood with LR? |
Ca in LR when combined with citrate in blood can form microclots (citrate is the anticoagulant found in donor PRBCs) |
|
What can happen with citrate intoxication? |
hypocalcemia with its associated problems of seizures, tetany, laryngospasm, hypotension, narrow pulse pressure, QT prolongation, elevated end diastolic pressure and CVP |
|
What are the indications for giving FFP? |
1. replacement of isolated factor deficiencies |
|
What are signs of a hemolytic transfusion reaction under anesthesia? In the awake pt? |
1. hemoglobinuria |
|
What are consumed in DIC? |
1. clotting factors (esp 5 and 8) |
|
What are lab findings suggestive of DIC? |
1. PT > 15 s, |
|
What are causes of DIC? |
SATT: |
|
What is cryo used for? |
1. replace factor VIII, |
|
what is the problem with commercially prepared fibrinogen? |
high incidence of associated hepatitis |