Evaluation of a Bleeding Patient Flashcards
What are the steps in platelet plug formation?
a. PLATELETS attach to exposed collagen
b. aggregation trigger (ADP and TXA2 release)
c. ADP attracts more platelets
d. TXA2 causes vasocontriction
Suppose you get a patient that clots after being cut then bleeds again in 6-9 hours. What should you consider?
Factor XIII mutation
What 4 types of bleeding are you likely to see with bleeding disorders?
- Purpura
- Petechiae
- Ecchymoses
- Hemarthroses
T or F: Portal HTN can be a sign of low platelets.
True
What nutritional defects have the potential to lead to thrombocytopenia?
• What are some things that should be in your ddx for thrombocytopenia?
Nutritional:
• B12 or Folate Deficiency
Others:
Bone marrow failure, Chemo/Rad Exposure, Marrow infiltration
What level of platelets is classified as thrombocytopenia?
Less than 150,000
You see large platelets on the peripheral smear and a patient is thombocytopenic. What is most likely the cause of the thrombocytopenia?
Increased Consumption of Platelets: • ITP • HIT • HUS • TPP • DIC
How would you run through the DDx of a 75 yr old man who has macrocytosis, pancytopenia, and a low platelet count?
Nutritional - Run Tests
• B12, Folate
Alcohol or Medications - Get from Hx.
If all else is negative take a bone marrow biopsy to test for Myelodysplasias or other pathologies
At what percent platelet hypoaggregation do you begin to suspect qualitative disorders?
less than 20%
In what cases might a patient who is actually hypercoagulable present with a lower PTT?
Lower PTT:
• Lupus Anticoagulant - in vivo it promotes thombosis, but in vitro it blocks phospholipids that act as a platform for catalysis of promthrombin activation
Lower PTT:
• Factor XII deficiency in vitro causes Hypercoagulable state
What is hemophilia C?
• How is it inherited?
• Epidemiology?
• Prolonged PT or PTT?
Factor XI deficiency
Inherited as Autosomal Recessive in A. Jews
**PTT prolonged
How are Hemophilia A and B inherited?
X-linked Recessive
If von Willibrand’s disease is present will you see a change in PT or PTT?
PTT is prolongued but not always - this makes sense because vW being low would lead to Factore VIII being destabilized
If someone has an autoimmune disease, what types of bleeding disorders should you expect?
Things that are Antibody Mediated like ITP and Lupus Anticoagulant
What clotting factors would be depressed in:
• Liver Disease
• Vitamin K Deficiency
• DIC
Liver Disease:
• Decreased V, VII, X
Vit. K Deficiency:
• Decreased VII, X
DIC
• Decreased V, VII, VIII, X
When taking Warfarin, what happens to the PT and PTT in the short term and Long Term?
Short Term:
• HIGH PT (because of factor VII decrease)
Long Term:
• HIGH PTT and PT (because of
What clotting factors are Vit. K dependent?
• Factor II, VII, IX, X, protein C and S.
What are some factors that can cause a Vit. K deficiency?
- Nutritional Deficit
- Antibiotic Use
- Fat Malabsorption
How would you treat a vitamin K deficiency?
Mild:
• Vit K replacement
Severe:
• Fresh Frozen Plasma
Is Vit. K replacement an effective way to treat Clotting Factor deficiencies caused by Liver Disease?
• What if fibrinogen is low?
NO, the liver can’t do anything with the Vit. K, you should give these patients Fresh Frozen Plasma (all clotting factors)
Low Fibrinogen
• Cryoprecipitate (with Fibrinogen, VIII, XIII, and vWF would do)
What’s the idea behind giving a patient IVIG or anti-Rh?
IVIG:
• Throwing a dog a bone…Spleen will have to take up Ig therefore it won’t attack the platelets bound by ig
anti-Rh:
• Causes RBC lysis and the liver and spleen attack the remnants and it prevents them from attacking platelets
What common bacteria is associated with ITP?
H. Pylori
Why do you see elevated LDH in the microangiopathic hemolytic anemia/thrombocytopenia?
- Anoxic Injury - blood isn’t getting to the periphery so cells there die without oxygen
- RBC lysis - lots of LDH because all they can do is glycolysis
**Not Seen in Extravascular Hemolysis Diseases
What are the effects of Hemoglobin that results from extravascular hemolysis?
- HEMOSIDEROSIS in kidney’s
- LOW Haptoglobin
- HIGH Unconjugated/Direct Bilirubin
Compare the following for extravascular and Intravascular hemolysis:
• LDH
• Bilirubin
•Haptoglobin
Intarvascular:
• LDH - VERY ELEVATED
• Bilirubin - Elevated
• Haptoglobin - ABSENT
Extravascular:
• LDH - elevated
• Bilirubin - elevated
• haptoglobin - Normal/absent
Compare the following for extravascular and Intravascular hemolysis:
• Hemoglobinurea
• Free Hb
• Urine Hemosiderin
Intravascular:
• Hemoglobinurea - present
• Free Hb - present
• Urine Hemosiderin - present
Extravascular:
•Hemoglobinurea - absent
• Free Hb - Absent
• Ureine Hemosiderin - absent
T or F: ITP causes microangiopathic Hemolytic Anemia
False, diseases like TTP, HUS, and DIC do this
Which of the following microangiopathic hemolytic anemias corrects on a mixing study? Explain. • HUS • TTP • DIC • aHUS • SLE
ONLY DIC will correct in a mixing study because it is not antibody mediated and there will be enough factor to make a clot
• IN all the others the amount of antibody in the plasma will block clot formation
What causes are some factors besides sepsis that can cause DIC?
- Metabolic Stress
- Obsterical Complication (pre-eclampsia/eclampsia)
- Malignancies
- Severe Burns
What single lab test can tell you that someone is in DIC?
NONE, it takes SEVERAL lab tests to confirm DIC
How do you treat DIC?
DIC is treated by treating the organism or disease that is causing DIC
What should be on your differential for DIC?
- Severe Liver Failure/Liver Disease
- Vit. K Deficiency
- TTP
- Congenital Abnormalities of Fibrinogen
- HELLP syndrome
When is plasma Therapy given:
ONLY indicated in ACTIVE bleeding (or invasive procedures)
Avoid having to do this in procedures by choosing a tamponadable site (e.g. put a central line into the femoral artery instead of subclavian etc.)
What is a good option to give your patient if they only need fibrinogen?
• Cryoprecipitate (provides vWF, VII, X, and fibrinogen)
When do you give a whole blood transfusion?
• how much do you give?
Indication:
- Active Bleeding
- Loss of RBCs in hemolysis
1 unit/10kg
Should you give heparin during DIC?
• Use is very controversial MAYBE implicated with evidence of fibrin deposition and a large clot
When should you start getting suspicious of HIT?
ANYONE who has been in the HOSPITAL recently or has had a procedure done that may have required heparin.
What is the pathophysiology of HIT?
- Heparin Binds to PF4 on the platelet
- Ab. binds the Heparin:PF4 combo after it dissociates from the surface
- Fc receptor on the platelet binds Fc region on Ab
- Macrophages in the Spleen Remove the Platelet
T or F: everybody that has HIT associated antibodies needs to avoid heparin
FALSE, many people have HIT associated Abs. HOWEVER only a small portion of these patients will have the HIT syndrome itself
**30% of the population is positive for these abs. but only a small portion would ever experience HIT
What test would you for sure want to use on a patient with an autoimmune disease if testing for HIT?
Serotonin Assay (aka Functional assay)
How does the pyrimid model apply to HIT?
Thrombosis: only 0.2-1.0% of ppl.
Thrombocytopenia: only 1-3% of ppl.
30% are + for the Heparin Ab.
**What are the 4 Ts of determining whether or not to run a Heparin Lab Assay.
Thrombocytopenia: >50% (2); 30-50% (1)
**Timing: 5-10 days or less than 1 with prior exposure
Thrombosis: New Thrombosis, Skin Necrosis
oTher cause: none (2); possible (1)
**test anyone with 5 or higher
T or F: if someone has a weakly positive immunologic Heparin assay, you might still want to run a functional assay because they still might have HIT.
TRUE, this would happen if the clinical probability of them having the disease was high
(functional assay = serotonin assay)
T or F: its still only to give Low Molecular Weight Heparin with HIT.
FALSE
