10. Hemostasis (Disorders)

Question 1

clinical sxs of platelet problems

Answer 1

pretechiae (small spots, mini hemorrhages), bruising (ecchymoses), mucosal bleeding

Question 2

differentiating VWD from platelet probs

Answer 2

○ VWD is inherited - vast majority of platelet probs are acquired
○ VWD is life-long - platelet probs are acute
○ VWD a/w family history - platelet probs usu not

CBC gives the answer

Question 3

von willebrand’s disease

Answer 3

○ Most common inherited bleeding disorder
§ 1:1000 indivs
○ Autosomal dominant
○ Symptoms
§ Mucosal bleeding
□ Nosebleeds
□ Prolonged bleeding w/dental work
□ Heavy menses
□ Easy bruising
® Most pts do not accurately report
□ Excessive bleeding w/surgery
○ Type 1 - common and generally mild until pts stressed w/maj injury or surgery
§ Hx taking for this is “did you tolerate prior surgery?”
□ But most pts haven’t had
○ vWF synthesis
§ Large pre-pro-vWF
§ proVWF monomer = mature VWF + propeptide
§ proVWF dimerize in ER
§ Complex dimers joined in the Golgi and pro-peptide is removed

Question 4

defects in single coagulation factor

Answer 4

○ Factor VIII & IX deficiency: x-linked recessive
○ Factor XII deficiency: autosomal recessive
○ Abnormal on PT
§ VII
○ Abnormal on PTT
§ VIII, IX, XI, XII
□ VIII and IX more severe bleeding than XI
□ XII doesn’t cause any bleeding
□ *the lower the factor, the worse the bleeding
○ Abnormal PT and PTT
§ II, V, X, fibrinogne

Question 5

hemophilia A

Answer 5

Hemophilia A (Factor VIII Deficiency)
			§ Clinical manifestations
				□ Bleeding	
					® Deep
					® Delayed
				□ Severity (100% is mean normal level, 50%-150% is normal)
					®

Question 6

acquired factor VIII inhibitor

Answer 6

□ Antibody vs factor VIII
□ Elderly pts
□ - Antibody vs factor VIII
- Elderly pts
- Also seen postpartum, pts rheumatologic disease, malignancy
- Presents w/soft tissue bleeding
** if see a big mass on thigh and elevated PTT, often MDs suspect tumor or acute compartment syndrome, but IT’S NOT, IT’S THIS
® If have high titer inhibitor they will not overcome bleeding because factor VIII absorbed completely by inhibitor

Question 7

vit K deficiency

Answer 7

§ If severe, see prolonged PT and PTT
§ Commonly only see prolonged PT
□ Factor VII has a short half-life so more severe

Activates factors II, VII, IX, X by adding glutamic acid to them

§ Causes
	□ Dietary defic
		® Only in young kids with no gut bacteria
		® Only seen in adults with comorbidity - diet doesn’t cause vit K deficiency alone
	□ Antibiotics
		® Gut make Vit K
		® Common in hospitalized pts w/infection post op
	□ Malabsorption
	□ Newborn
	□ Coumarins
		® Including bat poison
		® Warfarin
			◊ Blocks recycling of vit K causing deficiency
			◊ Followed using PT
§ Tx
	□ Vit K
		® Carefully if you want to put pt back on warfarin
		® Monitor
	□ Plasma
		® Short-term fix only
		® Only as long as factor w/ shortest 1/2 life - Factor VII
	□ Kcentra
		® Life threatening emergencies
			◊ Provides all missing vit K factors
			◊ Expensive

Question 8

heparin acts on what factors?

Answer 8

XI, IX, X, II (thrombin) – follow with PTT

Question 9

DIC

Answer 9

§ Disseminated intravascular coagulation (DIC)
				□ Sepsis
				□ Viral hemorrhagic fevers (ebola)
				□ Trauma
					® Crush, head injury, fat embolism
				□ Cancer
					® MPD, pancreas, prostate
				□ Lab findings
					® Prolonged PTT

Question 10

most common severe inherited thrombophilic disorder

Answer 10

anti-thrombin III deficiency

Question 11

risk factors for VTE

Answer 11

§ Lots of reasons for VTE
□ Eg cancer pt more likely to have DVT than person w/factor V Lieden mutation
□ Only think of below risk factors in a specialized way
□ Over 50, don’t need a reason for DVT
§ Acquired risk factors
□ Antiphospholipid syndrome
§ Inherited risk factors
□ Antithrombin defic, protein C or S defic, factor V Leiden mutation, prothrombin G20210A mutation

Question 12

causes of inherited thrombophilia

Answer 12

§ Lots of reasons for VTE
□ Eg cancer pt more likely to have DVT than person w/factor V Lieden mutation
□ Only think of below risk factors in a specialized way
□ Over 50, don’t need a reason for DVT
§ Acquired risk factors
□ Antiphospholipid syndrome
§ Inherited risk factors
□ Antithrombin defic, protein C or S defic, factor V Leiden mutation, prothrombin G20210A mutation

Common causes w/lower thrombotic risk
- Factor V Lieden
○ Common mutation that keeps V alive longer than it should be
- Prothrombin 20210

Hyperactivity of enzyme

Question 13

hemostatic deficit involving several pathways: severe liver disease

Answer 13

○ Affects multiple things w/in the clotting pathway but the proteins that inhibit clots are also made in the liver = rebalanced homeostasis
○ PT and PTT long because take longer to form clots
○ Also problem inhibiting clots (But we don’t measure that so you can’t really tell)
○ Risk for bleeding or thrombosis
§ Perhaps tx w/anticoagulant that doesn’t need PT/PTT levels because they will be long
- Dx of coagulopahty can be challenging
○ Re:overlapping problems