Nikcevich- Clincal Cases in Coagulation Flashcards
What is a normal platelet count?
150-400,000
What happens if the platelet count is 25,000
Probably nothing
What happens if the platelet count is <10,000
Increased risk of mucocuntaneous bleeding and CNS hemorrhage
What is more important in regards to platelets than the actual number of platelets?
Platelet surface area
What is the most common reason for impaired platelet function?
Aspirin
INR is used to usually monitor what drug?
Warfarin efficacy
What is the target INR?
2-3.5
What does PTT measure?
heparin efficacy
NOT LMW heparin
What is the single worse clinical test available?
Bleeding time
was designed to measure platelet function
What is the most common cause of increased bleeding time?
Aspirin
What does Aspirin do?
Irreversibly acetylates platelets
How long does aspirin’s effects last for?
Up to 10 days
How do you reverse aspirin?
Wait 10 days and see if you can give platelets
What do ibuprofen, naproxen, etorolac, sulindac and indomethacin do?
Reversibly effect platelet function
**effects can be reversed w/in 6-8 hrs
What is the most common anti-coagulant?
Warfarin
Interferes w/ vit K dep secondary glycosylation of factors 2,7,9,10
How is warfarin dosed?
Accodring to INR
What is the biggest disadvantage of Warfarin?
It has a lot of drug interactions
How do you reverse warfarin?
Time
vit K
Fresh frozen plasma
What type of heparin has the most reliable absorption?
LMWH- no need to monitor levels
Unfractionated has UNPREDICTABLE absorption–need to monitor daily w/ PTT
When is clopidogrel used?
After cardiac stents/ stroke
What does tPA do? When is it used?
Responsible for direct fibrinolysis.
MI, stroke, PE
What does vit K do?
Reverses effects of warfarin
often helpful w/ coagulopathy of liver disease
(phytadione)
What does DDAVP do?
Increases vWF prodcution
What does fresh frozen plasma do?
Gets all coagulant factors to normal levels
can reverse warfarin effects/replace factors missing d/t liver disease/DIC
What does cryprecipitate do?
Provides fibrinogen, VWF, facotr 8 and 13, fibronectin
What is commonly sen w/ platelet defects?
Prolonged bleeding
petechiae and easy bruising
skin and mucous membranes
non-recurrent bleeding
What is seen w/ coagulation defects?
pro-longed bleeding
deep hematomas
recurrent bleeding
What do you think when you see an elevated PTT?
Heparin?
Lupus-anticoagulant or antiphospholipid Ab?
Liver disease
How do you diagnose a problem from a prolonged PTT?
Do a mixing study
corrects- lab error, heparin contamination
don’t correct- LAC or inhibitor
What are causes of prolonged INR?
Warfarin use- most common
anti-phospholipid ab
liver disease
malnutrition (vit K def)
How do you determine the cause of prolonged INR?
Mixing study
corrects– lab error/factor def
doesn’t correct– anti-phospholipid ab or inhibitor
What can cause thrombocytosis?
Increased platelets can be caused by secondary processes like IDA
or primary processes like a myeloproliferative disorder
How long should a pt w/ uncomplicated non-life-threatening DVT/PE be given Warfarin?
At least 6 months of warfarin w/ target INR 2-3
How long should you treat someone with life-threatening DVT/PE/arterial thrombosis?
indefinite anticoagulation
How long should you treat a second DVT/PE that isn’t life threatnening?
Indefinitely
How long should you treat an uncomplicated first DVT/PE in someone who is homozygous for an inherited coagulopathy?
indefinitely
How long should you treat an uncomplicated first DVT/PE in someone who is heterozygous for an inherited coagulopathy
At least 6 mos w/ target INR 2-3 or longer
What does an IVC filter do?
Traps any PE. Most frequently used in preoperative pt w/ increased risk for DVT/PE
Requires anti-coagulation
Why do you bridge w/ heparin?
Because many pro-coagulant factors have a longer half life than protein C.
Factor III t 1/2 = 60 hrs
F VII= 6 hrs
Protein C t1/2 = 9 hrs
What is a surrogate marker for low prot C?
HIGH INR
low factor VII
A pt who is managed w/ warfarin develops epistaxis and has an INR of 10. What do you order for them?
2 mg PO x1 of Vit K
How do you treat ITP- immune mediated thrombocytopenia?
Prednisone at 1mg/kg daily
Pulse dexamethasone 40 mg po qdx4d
Very common- low platelets
How do you treat a pt who has ITP and a platelet count of 65k?
Observe w/ serial monitoring
