Part 2 HEME Review Exam

What is the treatment for this TEG tracing?

R Time: 7 min

K Time: 2 min

Alpha Angle: 56 degrees

MA: 61 mm

LY30: 5%

• Normal - no treatment

What is the treatment for this TEG?

R Time: 15 min

K time: 4 min

Alpha angle: 50 degrees

MA: 60 MM

LY30: 4%

• treatment: cryoprecipate

What is the treatment for this TEG?

R time: 10 minutes

K Time: 3 minutes

Alpha Angle: 57 degrees

MA: 57 mm

LY30: 35%

• treatment: antifibrinolytic (TXA)

What is the treatment for this TEG?

R Time: 20 min

K time: 5 min

Alpha angle: 45 degrees

MA: 39 mm

Ly30: 4%

• Treatment: PLTs

What is the treatment for this TEG?

Increased R time

Increased K

normal alpha

normal MA

normal Ly30

• treatment: FFP

What is the pathophysiology of Glanzmann’s Thrombocytopenia?

• rare, autosomal recessive disorder of PLT function caused by a deficiency of GPIIb/IIIa

  • gene defect on chrom 17

What lab finding indicate Glanzmann’s Thrombocytopenia?

• PLTs = normal

• PLT morph. = normal

• BT = prolonged

• clot retraction = abnormal

• Aggregation Studies

  • Normal: ristocetin and ADP

  • Abnormal: thrombin, collage, epinephrine

What treatment is used for Glanzmann’s Thrombocytopenia?

• plt transfusion judiciously

• antifibrinolytics

What is the pathophysiology of Bernard-Syndrome?

• caused by a deficiency of the PLT GPIb receptor

• also acquired due to formation of antibodies to GPIb

What treatment is used for BSS?

• antifibrinolytics

• RBC transfusions

What lab findings indicate BSS?

• normal/reduced PLT count

• large PLTs on blood smear

• prolonged BT

• normal number of megakaryocytes seen in bone marrow

• normal aggregation: ADP,epinephrine, collagen

• reduced aggregation: thrombin

• no aggregation: risopetin

• RIPA absent

Describe the Initiation Phase of the Cell based model of coagulation?

• generation of small amount of F: IXa, Xa, and thrombin by TF and FVII complex

• cells involved: TF-bearing cells

Describe the Amplification Phase of the Cell based model of coagulation?

• activation of PLTs

• release of vWF from endothelial cells

• activation factors: V,VII, XI on PLT surface

• cells involved: PLTs

Describe the Propagation Phase of the Cell based model of coagulation?

• generation of factor Xa, IXa-VIIIa complex and prothrombinase (Xa-Va) on PLT surface

• massive generation of thrombin

• linkage of activated PLTs by fibrinogen through activated GP IIb/IIIa receptors

• cells involved: activated PLTs

What is the cause of a Factor V Leiden?

• mutation in the FV gene occurs in an. arginine to glutamine substitution at position 506

  • arginine is the usual cleavage site for APC to begin breaking down a clot

Describe the pathophysiology of Factor V Leiden.

• causes someone to have resistance to APC (anticoagulant)

• APC normally breaks down factor 5a and 8a when clot is not needed

• this mutation causes resistance which leads to:

  • decrease in breaking down of clots

  • faster coagulation with APC present

What is used to treat TTP?

• plasma exchange

• Cryo-poor plasma

What is TTP?

• triad of : MAHA, thrombocytopenia, neurologic abnormalities

• linked to deficiency in ADAMTS13

Describe the etiology of TTP.

• deficiency of ADAMTS13

• accumulation of large vWF multimers

• PLT aggregation + microthrombi

• neurologic abnormalities

What lab findings indicate TTP

• blood smear

  • schistocytes, microsceocyties, polychromasia, low PLTs

• decreased haptoglobin

• hemoglobinemia/hemoglobinuria

• PT,APTT, fibrinogen, D-dimer normal

• decreased ADAMTS13

What occurs in Primary Fibrinolysis?

• fibrin degradation products and D-dimer

  • plasmin degrades fibrin

• Steps

  • fibrinolytic proteins become imcorperated into fibrin clot

  • TPA and UPA convert plasminogen → plasmin

  • normal bloodflow restores when fibrin is degraged

What occurs during secondary fibrinolysis?

• plasmin is produced in the absence of fibrin clots

• associated with medical procedures involving kidney

• urokinase is released

What is Tissue Plasminogen Activator (TPA)?

• anticoagulant that attaches to fibrin clot

• activates plasminogen and forms plasmin

What is plasmin

• serine protease

• digest fibrin by hydrolysis of arginine and lysine peptide bonds

• as fibrin is degraded, carboxyl terminal lysine residues bind additional plasminogen and TPA

What occurs during PLT aggregation?

• PLT becomes activated when PLT GPIB receptor adheres to VWF

• PLTs change shape, contract, and release graules

  • alpha granules

  • dense ganules

    • ADP

      • tells PLTs to aggregate

      • activates GP2b/3a receptor on PLT

    • thromboxane 2A

      • promote PLT aggregation, vasoconstriction, bronchoconstriction

• ADP stimulare receptor and fibrinogenmolecule attaches to PLTS

• fibrinogen → fibrin and RBC will be trapped and a larger and larger PLT forms

What is Von Willebrand’s factor (vWF) and what does it do?

• facilitates adhesion of PLTs

Describe the roll of vWF in plt adhesion.

• vessel damaged / collagen is exposed

• vWF is secreted by endothelial cells/ binds to collagen

• PLTs have vWF receptors (GP1B) that bridge vWF proteins and connect PLTs to collagen

• this activates PLTs/ causes shape change

• PLT activation → express fibrinogen receptor GPIIb/IIIa

  • release of alpha / dense granules