10. Coagulopathy Flashcards
Coagulopathy is a complication of what underlying disease?
Cirrhosis (liver disease)
In cirrhosis, liver cells are replaced by what?
fibrosis
High amount of fibrosis results in _______ (↑/↓) blood flow to and through the liver.
decrease ↓
What are 4 complications of cirrhosis?
- splenic congestion
- portal hypertension
- fluid accumulation
- increased bilirubin
What is the consequence of splenic congestion?
thrombocytopenia
What is thrombocytopenia?
deficiency in platelets
What is a consequence of portal HTN?
varices
What is a consequence of fluid accumulation?
ascites
What are signs of increased bilirubin?
jaundice
dark urine
What is the threshold of diagnosing thrombocytopenia?
platelets < 150,000
What are the causes of coagulopathy in cirrhosis?
hepatocyte loss (diminished synthetic function) thrombocytopenia
Portal vein thrombosis is a very rare complication of liver cirrhosis. (T/F)
False: it is a fairly common complication
A randomized controlled trial has shown that what medication is effective for primary prevention of PVT in liver cirrhosis?
anticoagulation therapy
What is unfractionated Heparin?
heterogeneous mixture of glycosaminoglycans
MW = 3,000 - 30,000 daltons
What is the MOA of unfractionated Heparin?
binds to and catalyzes antithrombin III
inactivates factors IIa, Xa, IXa, XIa, XIIa
What makes unfractionated Heparin have variable pharmacokinetics and anticoagulant response?
binds to endothelial cells, macrophages, platelets, and plasma proteins
What are 3 contraindications of unfractionated Heparin?
there are 5 total
- active bleeding
- hemophilia
- thrombocytopenia
- intracranial hemorrhage
- severe hypertension
What are 3 ADRs of unfractionated Heparin?
- bleeding
- osteoporosis
- heparin induced thrombocytopenia
What monitoring is required for Heparin?
- aPTT (1.5 - 2.5 times control value)
- platelet count
- hemoglobin and hematocrit
- bleeding
With regards to unfractionated Heparin, what specific factors should be considered with the aPTT?
anti-factor Xa level 0.3 - 0.7 IU/mL
check q 6 hrs - adjust dose according to protocol
check q 24 hrs after 2 aPTTs within therapeutic range
What is low molecular weight Heparin?
polysulfated glycosaminoglycans
MW = 4,000-5,000 daltons
What is the MOA of low molecular weight Heparin?
binds and catalyzes antithrombin III
Why does low molecular weight Heparin have superior pharmacokinetics to unfractionated Heparin?
reduced binding to plasma proteins
reduced binding to macrophages and endothelial cells
reduced binding to platelets
What are the low molecular weight Heparin agents?
enoxaparin (Lovenox)
Dalteparin (Fragmin)
Enoxaparin and Dalteparin have identical molecular weights and can be used interchangably. (T/F)
False: they differ in mean molecular weight and are not created equally
What is the MOA of Warfarin?
The initial formation and propagation of thrombus is prevented because warfarin suppresses the production of clotting factors.
Warfarin has no direct effect on previously circulating clotting factors or previously formed thrombus. (T/F)
True
The full antithrombic effect of Warfarin may take how long to achieve?
1 week +
What is suggested for VTE prophylaxis in moderate to severe liver disease
usual approaches for hospitalized and post-op patients
What is suggested for acute VTE with elevated INR in moderate to severe liver disease
consider LMWH monotherapy
possible VKA but INR is difficult to monitor
DOACs should be avoided
if anticoagulation is not an option, IVC filter
What is suggested for atrial fibrilation in moderate to severe liver disease
baseline INR < 1.5 : oral anticoagulation
elevated baseline INR : may consider single or dual antiplatelet therapy
What is suggested for mechanical heart valve in moderate to severe liver disease
VKA until risk exceeds benefit
