Class 20 review

Question 1

aPTT purpose and normal value

Answer 1

Activated partial thromboplastin time
Assessment of intrinsic coagulation by measuring factors I, II, V, VIII, IX, X, XI, XII

Measured in seconds how long to clot

25-35 sec

Question 2

D-dimer purpose and normal value

Answer 2

Measures fragment of fibrin that is formed due to fibrin degradation/ clot lysis. Tells you that the clotting process is occurring in the body

<250 mcg/L

Question 3

INR purpose and normal value

Answer 3

International normalized ratio
Standardized way of reporting PT - compares PT with a control value

0.8-1.2

Question 4

PT purpose and normal value

Answer 4

Prothrombin time
Assessment of extrinsic coagulation by measurement of factors I, II, V, VII, X

11-16 sec

Question 5

Platelet count purpose and normal value

Answer 5

Count of number of circulating platelets

(150 x 10^9)/L to (400 x 10^9)/L

Question 6

What is VTE?

Answer 6

vein inflammation with a resulting thrombus

Question 7

Important factors for the etiology of VTE

Answer 7

Venous stasis
Endothelial damage
Hypercoagulability of the blood

Question 8

Venous stasis

Answer 8

Dysfunctional vein valves
Inactive extremity muscles
Change in unidirectional blood flow

Question 9

Endothelial damage

Answer 9

Release of clotting factors

Activation of platelets

Question 10

Blood hypercoagulability

Answer 10

Imbalance in clotting mechanism → coagulation

Increase in fibrin production

Question 11

Clinical manifestations of VTE

Answer 11

Unilateral leg edema
Pain
Tenderness with palpitation
Dilated superficial veins
Sense of fullness in legs
Paresthesias (tingling)
Warm skin but body temp <38 degrees C

Question 12

Symptoms of thrombocytopenia

Answer 12

Bleeding (mucosal or cutaneous)
Petechiae
Ecchymoses (discolouration of skin from bleeding underneath)
Prolonged bleeding
Hemorrhage

Question 13

Immune Thrombo-Cytopenic Purpura (ITP)

Answer 13

Acquired/Immune
Platelets are mistakenly coated with antibodies when they reach the spleen they are destroyed by macrophages within 1-3 days

Question 14

Thrombotic Thrombo-Cytopenic Purpura (TTP)

Answer 14

Acquired/Non-Immune
Typically has an underlying cause (e.g. infection). There is an enhanced agglutination of platelets which form microthrombi that deposit in arterioles and capillaries. It is a medical emergency.

Question 15

Heparin Induced Thrombo-Cytopenia with Thrombosis (HIT or HITT)

Answer 15

Acquired Nonimmune
Thrombocytopenia develops 5-10min after heparin therapy is started
Venous thrombosis and arterial thrombosis can develop
Body begins to attack platelets as a result of drug therapy

Question 16

Acquired Thrombocytopenic from Decreased Platelet Production

Answer 16

Acquired Nonimmune
The body does not produce as many platelets because there is an external factor inhibiting production. It can be from a disease or causative agent (e.g. drug). This is common in chemotherapy for cancer treatment.

Question 17

Platelet level 150 X 10^9/L

Answer 17

This is considered thrombocytopenia

Question 18

Platelet level 50 X 10^9/L

Answer 18

Prolonged bleeding will occur with trauma or injury

Question 19

Platelet level 10 X 10^9/L

Answer 19

Spontaneous life-threatening bleeding

Question 20

Thrombus definition

Answer 20

formed clot in the vascular system

Question 21

Emboli definition

Answer 21

a blockage that has moved from one part of the vascular system to another

Question 22

Phlebitis definition

Answer 22

inflammation (redness, tenderness, warmth, mild edema) of a superficial vein without the presence of a thrombus – very common with IV therapy

Question 23

Superficial Vein thrombosis definition

Answer 23

thrombus in a vein near the skin surface – generally benign

Question 24

Deep Vein thrombosis (DVT) definition

Answer 24

thrombus in a deep vein, most commonly the iliac and femoral veins of the leg – varies in severity – reduces blood return from the limb, increases vessel distention/edema distal to the blockage, thrombo-emboli may break away and travel to the lung causing a Pulmonary Embolism (PE – potentially life threatening). May be a long clot with a tail.

Question 25

Superficial Vein Thrombosis clinical manifestations

Answer 25

* Usually superficial leg veins- sometimes in the arms * Tenderness, rubour, warmth, pain, inflammation and induration along the vein * Vein appears as a palpable cord * Edema rarely occurs * If left untreated, DVT can occur

Question 26

Deep Vein Thrombosis clinical manifestations

Answer 26

* Deep veins of the arms, legs, pelvis and pulmonary systems * Tenderness or pressure over involved vein, induration of overlying muscle, venous distension, edema, mild to moderate pain, deep rubour, increased temperature * Pulmonary HTN, post-thrombotic syndrome may occur

Question 27

Risk factors for venous thrombo-embolism

Answer 27

``` Venous stasis Hypercoagulability of blood Dehydration or malnutrition Erythropoiesis-stimulating drugs (eg epoetin alfa [Eprex]) Oral contraceptives Polycythemia vera Endothelial damage ```

Question 28

Life Threatening Complication of VTE: Pulmonary Embolism

Answer 28

* Blockage of pulmonary artery by air, fat, tumor tissue or a thrombus * Lodges in blood vessel obstructs perfusion of alveoli * 30% mortality in untreated clients * Diagnosis plus anticoagulant therapy mortality rate is 6-8%

Question 29

Anticoagulant drugs

Answer 29

For arterial and venous thrombosis Heparin (enoxaparin) Warfarin (for long term)

Question 30

Antiplatelet drugs

Answer 30

For arterial disease Aspirin Clopidogrel

Question 31

How Thrombolytics Work

Answer 31

• Thrombolytic medications are mostly used during acute stroke or acute myocardial infarction • They are used to destroy the clot and restore perfusion in the brain and heart Are expensive, dangerous, high risk

Question 32

Heparin MOA

Answer 32

Activates antithrombin, which then inactivates thrombin and factor Xa

Question 33

Route, onset, duration, monitoring for heparin

Answer 33

Route: IV or subQ Onset: Rapid (minutes) Duration: Brief (hours) Monitoring: aPTT or anti-Xa heparin assay

Question 34

Warfarin MOA

Answer 34

Inhibits synthesis of vitamin K-dependent clotting factors, including prothrombin and factor X

Question 35

Route, onset, duration, monitoring for warfarin

Answer 35

Route: PO Onset: Slow (hours) Duration: Prolonged (days) Monitoring: PT (INR)

Question 36

Reversal agent of heparin

Answer 36

protamine

Question 37

Reversal agent of warfarin

Answer 37

vitamin K

Question 38

Antifibrinolytic agents (e.g. aminocaproic acid)

Answer 38

* IV/PO administration * Inhibit fibrin breakdown by inhibiting the formation of plasmin from plasminogen * Helps to keep bleeding episodes under control (nose, mouth, throat and post-dental extractions) * Most useful for preventing recurrent bleeding/less helpful in stopping an ongoing bleed

Question 39

``` Which of the following laboratory information should the nurse monitor to detect heparin-induced thrombo-cytopenia (HIT) in a client who is receiving a continuous heparin infusion? • Prothrombin Time (PT) • Red blood cell count • International Normalized Ratio (INR) • Activated prothrombin time (aPTT) ```

Answer 39

Activated prothrombin time (aPTT)

Question 40

A client with a venous thrombo-embolism (VTE) is started on enoxaparin and warfarin. The client asks the nurse why two medications are necessary. Which of the following responses by the nurse is accurate? • “Administration of two anticoagulants reduces the risk for recurrent venous thrombosis.” • “Enoxaparin will start to dissolve the clot, and warfarin will prevent any more clots from occurring.” • “The enoxaparin will work immediately, but the warfarin takes several days to have an effect on coagulation.”  • “Because of the potential for a pulmonary embolism, it is important for you to have more than one anticoagulant.”

Answer 40

“The enoxaparin will work immediately, but the warfarin takes several days to have an effect on coagulation.”