Hematologic Emergencies

Question 1

Only procoagulant not synthesized in the liver

Answer 1

Von Willebrands Factor (vWF)

Question 2

Extrinsic Pathway

Answer 2

Tissue Factor - III

VII

Triggered by Tissue Damage

Measure via PT

Question 3

Intrinsic Pathway

Answer 3

XII

XI

IX

VIII

Measure with PTT

Question 4

Common Pathway

Answer 4

X

V

II (prothrombin)

I (fibrinogen)

X is activated by both Extrinsic and Intrinsic pathways to cause fibrin clot formation

Question 5

Only factor deficiency that doesn’t cause coagulopathy

Answer 5

Factor XII

Question 6

Platelet Count

Answer 6

Normal is 150,000-400,000

If abnormal get smear

Low platelets may be caused by: Lasix, NSAIDs, sulfonamides, PCN, Autoimmune disease

Question 7

Prothrombin Time

Answer 7

Used to monitor Warfarin (INR)

Normal uncoagulated INR: 0.8-1.2

Evaluates VII (extrinsic), X, V, prothrombin, fibrinogen

Question 8

Partial Thromboplastin Time (PTT)

Answer 8

Monitor unfractionated Heparin therapy - also Warfarin

Not effective monitor for LMWH

Evaluates fibrinogen, prothrombin, V, VIII, IX, X, XI, XII (intrinsic and common pathway)

Question 9

Thrombin Time

Answer 9

Fibrinogen to fibrin conversion with abundant thrombin time

Prolonged: low/abnormal fibrinogen, low split products, Heparin

Used to check for DIC and chronic liver disease

Question 10

Von Willebrand Disease

Answer 10

Most common congenital bleeding disorder

Reduced VIII and vWF activity

vWF binds to factor VIII to prevent degradation

Mucocutaneous bleed

Prolonged PTT and abnormal platelet function

PT normal

Treat with Cryoprecipitate infusion or Desmopressin (DDAVP)

Question 11

Hemophilia

Answer 11

Reduced/absent factor VIII/IX activity

Males only

Joint or intramuscular bleed - swollen and painful

Bleeding from tissues, urinary, CNS - Internal bleed is biggest risk

No petechiae or ecchymosis

Prolonged PTT, normal PT and platelet function

Tx: Purified factor VIII/IX products

Question 12

Liver Disease Acquired Bleeding Disorder

Answer 12

Most common - no protein synthesis

Results in low prothrombin, V, VII, X

Obstructive jaundice and cirrhosis may also cause these

-Will respond well to Vitamin K

Question 13

Warfarin

Answer 13

Effects II, VII, IX, X

Reverse with FFP or Vitamin K in a hurry

Question 14

Heparin

Answer 14

Increases antithrombin III

Neutralizes IXa, Xa, XIIa and thrombin

Prolonged PTT and thrombin time

Often given during vascular surgery

Reverse with protamine sulfate

Question 15

Vitamin K-Dependent Factors

Answer 15

VII

X

Prothrombin (II)

Question 16

Coagulation Termination

Answer 16

Antithrombin (antithrombin III): neutralizes thrombin; heparin-like prevention of thrombus formation on endothelium

Tissue factor pathway inhibitor

Clotting-initiated inhibitory process - Protein C pathway

Question 17

Protein C and S

Answer 17

Plasma proteins

C: acts as anticoagulant protein - inactivates factors V and VIII

S: breaks down fibrin into degradation products which act as anticoagulants

Question 18

Signs of Anemia/Bleeding

Answer 18

Palpitations

Dizziness

Orthostatic HOTN

Exertional Intolerance

Tinnitus

Question 19

Secondary Hemostasis Disorders

Answer 19

Coagulation factor issues

Intrinsic: Hemophilia A&B, vWF

Extrinsic: Vitamin K deficiency

Question 20

3 Stages of Hemostasis

Answer 20

1. Vasospasm
2. Neutrophils migrate to site
3. Platelets migrate to site, make sticky by vWf

Question 21

Vitamin K Deficiency

Answer 21

Common in Alcoholics, liver disease, malabsorption, poor diet, long-term abx use

PT/PTT prolonged, PT more so

Decreased factors II, VII, IX, X and Proteins C&S

Treat: Vitamin K supplementation - doesn’t work with liver disease (liver doesn’t respond)

Question 22

Idiopathic Thrombocytopenia Purpura (ITP)

Answer 22

Antibodies bind to platelets and cause them to be cleared by spleen - no splenomegaly

Kids - often after viral infection; adults - transfusion, IVDA, Graves

Bruising, petechiae, purpura, epistaxis, retinal hemorrhage

Tx w/ platelets <50k or if bleeding - prednisone

Question 23

Secondary ITP Causes

Answer 23

Drugs: Sulfa, Thiazide, Cimetidien, Heparin

SLE

AI disease

Hepatitis

HIV

Question 24

Thrombotic Thrombocytopenic Purpura (TTP)

Answer 24

Abnormal activation of platelets nd endothelial cells with clot formation in microvascular and peripheral destruction of platelets and rbcs

Pentad: hemolytic anemia, thrombocytopenia, renal, neurologic, fever

Commonly in young females - pregnancy, drugs, infections, estrogen use

Treatment: plasma exchange; never transfuse w/ platelets, only makes it worse

Question 25

Hemolytic Uremic Syndrome (HUS)

Answer 25

Lacks the neurologic and fever of TTP

Diarrhea - e.coli/Shigella; often in kids

Renal failure, hemolytic anemia, thrombocytopenia

Question 26

TTP/HUS from DIC

Answer 26

Coags are normal with TTP/HUS

Question 27

Disseminated Intravascular Coagulation (DIC)

Answer 27

Both bleeding and thrombosis - bleeding MC

Digital ischemia/gangrene, renal necrosis, CNS and respiratory failure with shock and widespread bleeding

PT, PTT prolonged; positive D-dimer; low coagulation inhibitors (C) and coagulation factors as well as fibrinogen levels

Tx: correct cause, hemodynamic support with transfusions

Question 28

Anemia Murmur

Answer 28

Systolic murmur

Heart is having to work harder to pump - causes rapid flow with higher cardiac output and circulatory overload

Not a true murmur, just increased volume coming through

Heart has to work harder due to lack of oxygen

Question 29

Factor V Leiden Deficiency

Answer 29

MC clotting deficiency

Causes strokes, PE, pathologic clotting (DVT)

Factor V resistant to breakdown by activated protein C