Venous Thromboembolism (M4A)

Question 1

VTE (venous thromboembolism) is made up of…

Answer 1

• DVT (deep vein thrombosis)

- PE (pulmonary embolism)

Question 2

risk factors for DVT & PE

Answer 2

Virchow’s Triad:

• endothelial injury (creates site for clot formation)
• venous stasis
• altered coagulation

Question 3

endothelial injury causes

Answer 3

• trauma
• Sx
• repetitive motion injury
• pacing wires
• local vein damage
• dialysis & central catheters

Question 4

venous stasis causes

Answer 4

• bed rest or immobilization
• obesity
• Hx of varicosities
• spinal cord injury
• age (>65 yrs)

Question 5

altered coagulation causes

Answer 5

• cancer
• pregnancy
• oral contraceptive use
• clotting disorders
• protein C & S deficiency
• polycythemia
• discontinuation of anticoagulant use

Question 6

S&S of DVT

Answer 6

• swelling
• pain
• cool or warm to touch
• S&S can be nonspecific (asympt or have a “weird feeling”)

Question 7

S&S of PE

Answer 7

• dyspnea (SOB)
• tachypnea (rapid breathing)
• dec SpO2
• chest pain of a pleuritic nature (worsened by breathing)
• cough
• hemoptysis (coughing up blood)

Question 8

non-pharm nursing interventions

Answer 8

• monitor CWMS (color, warmth, movement, sensation)
• measure limb
• monitor skin integrity
• monitor for S&S of clots
• mobilization
• positioning
• compression stockings (if ordered)
• promote home, community based and transition of care

Question 9

pharm nursing interventions

Answer 9

• monitor and treat pain
• anticoagulants & thrombolytics
• for PE, admin O2

Question 10

drugs to treat DVT (medical management)

Answer 10

anticoagulants:
- LMW heparin (dalteparin & enoxaparin; 1st line of Tx)
- unfractionated heparin (IV)
- warfarin (PO)

Question 11

endovascular management for DVT

Answer 11

• used when anticoagulant or thrombolytic therapy contraindicated, risk for PE, or venous drainage compromised
• thrombectomy (mechanical method of clot removal)
• vena cava filter (traps large emboli and prevents PE)

Question 12

if pt receiving anticoagulant therapy, what lab values does nurse monitor?

Answer 12

• aPPTT
• prothrombin time (PT)
• INR
• ACT
• Hg & Hct
• platelet count
• fibrinogen level

Question 13

Dx tests for VTE

Answer 13

• D-dimer
• PTT, PT-INR
• WBC differential
• CBC
• U/S (for deep veins in legs)
• CT scan (chest r/t PE)

Question 14

D-dimer

Answer 14

= non-specific marker of fibrinolysis (for clotting)

• body’s natural rxn to clot development = fibrinolysis
• produced by the action of plasmin on fibrin polymer clot

Question 15

antiplatelets - action

Answer 15

• suppress platelet aggregation
• prevent thrombosis in arteries
• ex. aspirin

Question 16

aspirin (action, ADE & contraindications)

Answer 16

• action: suppresses platelet aggregation
• ADE: inc risk of bleeding (esp in GI)
• contraindications: not for children (Reye’s Syndrome), pregnant

Question 17

anticoagulants - action

Answer 17

• inc clotting time to prevent thrombi from forming/growing larger
• inhibit specific clotting factors in coagulation cascade
• do not “breakdown” clot (only prevents clots)

Question 18

anticoagulants - indications

Answer 18

• VTE prophalyxis
• Hx of DVT/PE
• dysrhythmias (A-fib)
• mechanical heart valve
• post-MI or stroke

Question 19

examples of oral anticoagulants

Answer 19

• direct thrombin inhibitors (dabigatran)
• direct factor Xa inhibitors (rivaroxaban, apixaban)
• vit K antagonist (warfarin)

Question 20

oral anticoagulant - important to know

Answer 20

• no routine monitoring of coagulation factors needed
• fixed dosage
• no antidote for OD
• avoid/limit IM injections (risk for hematoma)

Question 21

if pt receiving oral anticoagulant therapy, what does nurse monitor?

Answer 21

• S&S of bleeding (hematuria, epistaxis, bloody stools, bruising)
• VS
• lab values
• hepatic/renal failure
• possible drug interactions

Question 22

heparin (anticoagulant)

Answer 22

• given subQ or IV
• brief half-life
• antidote = protamine sulfate
• not usually given to prevent clots (pt has clot already)

Question 23

admin of heparin inc risk for…

Answer 23

• thrombocytopenia (heparin-induced)

- hemorrhage

Question 24

IV admin of heparin - important to know

Answer 24

• rapid onset
• weight based
• freq monitoring of PTT and signs of bleeding necessary

Question 25

subQ admin of heparin - important to know

Answer 25

• infreq monitoring of PTT
• monitor for signs of bleeding
• usually given BID/TID

Question 26

LMW heparin (anticoagulant)

Answer 26

• duration is 2-4x longer than heparin
• produces more stable response than heparin
• weight based dosage
• can be used at home
• monitor for S&S of bleeding

Question 27

LMW heparin examples

Answer 27

• dalteparin

- enoxaparin

Question 28

Vitamin K antagonist (anticoagulant)

Answer 28

• PO only
• can take 3-5 days to reach therapeutic level
• prevent thrombosis
• risk for hemorrage
• long half-life = 1-3 days
• monitor PT-INR
• antidote = Vitamin K
• many drug interactions

Question 29

Vitamin K antagonist example

Answer 29

• warfarin

Question 30

contrasts between warfarin and heparin

Answer 30

• warfarin PO; heparin injection
• warfarin inhibits synthesis of clotting factors; heparin inactivates thrombin & factor Xa
• warfarin effects begin slowly & persist for several days; heparin effects begin and fade rapidly
• monitor PT for warfarin; monitor aPTT for heparin
• vitamin K counteract warfarin; protamine counteract heparin