DVT

Question 1

DVT & PE together =

Answer 1

= venous thromboembolism (VTE)

Question 2

T/F DVT/PE rarely go undetected

Answer 2

False

DVT + PE often clinically silent (so incidence underestimated)

Question 3

Risk factors for DVT:

Answer 3

*Cause unknown but has to with 3 kinds of risk factors:
VIRCHOW's TRIAD:
1) Blood stasis
2) Vessel wall injury		
3) Altered blood coagulation

• Higher in men
• Those with hx of varicose veins, CVD, hypercoagulation, neoplastic disease
• Recent major surgery or injury at greater risk
• Obese
• Older adults
• Women on oral contraceptives

Question 4

S&S for DVT?

Answer 4

Swelling
Pain
Cool or warm to touch
Can be non-specific…..hard to diagnose

o Edema + swelling of extremities
o Compare bilaterally: affected limb may feel warmer than unaffected extremity, deep veins may be more prominent
o Tenderness (develops later) w inflm of vein wall
o Homan’s sign (pain in calf after food sharply dorsiflexed) NOT reliable!
o In some cases, manifestations of PE are first of DVT

Question 5

When does venus stasis result?

Answer 5

immobilization, obesity, hx of variscosities, spinal cord injury, age (

Question 6

Those factors that r/t endothelial damage as a risk factor for DVT?

Answer 6

trauma, sx, pacing wires, CVC’s, dialysis access catheters, local vein damage, repetitive motion injury

Damage to intimal lining creates site for clot formation → trauma d/t fractures & dislocation, disease of veins, chemical irritation from IV meds

Question 7

Which conditions cause altered coagulation?

Answer 7

cancer, pregnancy, oral contraceptive use, protein C or S deficiency, antithrombin III deficiency, polycythemia, septicemia, elevated factors II, VIII, IX, XI

Question 8

Why are those who are pregnant more at risk of DVT?

Answer 8

inc in clotting factors, can least up to 8 weeks postpartum

Question 9

Does DVT only occur in the deep veins?

Answer 9

Can occur in both superficial + deep veins, most often in lower extremities (but can occur anywhere)

Question 10

How does repetitive motion result in clots?

Answer 10

• Repetitive motion (as in competitive swimmers, construction workers) causes irritation of vessel wall → inflm → thrombosis = effort thrombosis

Question 11

What is recanalization and how does it r/t DVT?

Answer 11

• After DVT, recanalization (reestablishment of lumen of vessel) typically occurs

Question 12

phlegmasia cerulea dolens

Answer 12

massive iliofemoral venous thrombosis), in which enire extremity becomes massively swollen, painful, tense, and cool to touch

**Only kind of DVT with very specific symptoms

Question 13

What will you see with clots in superficial veins?

Are they as dangerous? How to treat?

Answer 13

o Pain + tenderness
o Redness, warmth in affected are
o Most dissolve – not great risk of embolism – can treat w bed rest, elevation of leg, analgesic agents, anti-inflm meds

Question 14

Key concerns in DVT assessment:

Answer 14

o Pain
o Feeling of heaviness
o Functional impairment
o Ankle engorgement
o Edema
o Differences in leg circ bilaterally from thigh to ankle
o Inc surface temp of leg (particularly in calf or ankle)
o Area of tenderness or superficial thrombosis

Question 15

Complications of DVT?

Answer 15

• Chronic venous occlusion
• PE
• Valvular destruction: chronic venous insufficiency, inc venous pressure, variscosities, venous ulcers)
• Venous obstruction: inc distal pressure, fluid stasis, edema, venous gangrene

Question 16

Characteristics of the deep veins?

Answer 16

thinner walls, less muscle in media, lie parallel to arteries (have same names)

Question 17

Important labs for DVT?

Answer 17

PTT, 
PT-INR
D-Dimer (not reliable)
ACT (?)
 Hb + HCt
platelet count
fibrinogen levels

Question 18

Nursing interventiosn for DVT?

Answer 18

• Close observation for bleeding → blood in urine, bruising, nosebleeds, bleeding gums
• Elevate feet + lower legs to level above heart, promote active + passive leg exercises
• Deep breathing (inc neg pressure in thorax…better venous return)
• Provide comfort + improve circ: elevate limb, use compression stockings, analgesic agents, application of warm, moist packs to affected area, bed exercises (repetitive dorsiflexion)
• Encouraged to walk once anticoag tx has been initiated

Question 19

What is often the first sign of too high dosage of anticoagulant?

Answer 19

blood in urine often first sign of excessive dosage

exmined by microscopy,

Question 20

What are graduated compression stockings?

Answer 20

NOT TED (anti-embolism) stockings…these have greater pressure (20-40mmHg rather than 12 to 20mmHg in TEDs)

o P depends on severity
o Designed to apply 100% of prescribed P gradient at ankle, decreases as approaches thigh
o May be knee high, thigh or pantyhose
o When off, inspect skin + palpate for calves for tenderness

Question 21

What is given to reverse the effects of heparin?

Answer 21

• Protamine sulfate given IV to reverse effects of heparin (risk bradycardia + hypotension…administer slowly!) – less but still some effectiveness with LMWH

Question 22

How to reverse warfarin?

Answer 22

Vit K

Question 23

Prevention of DVTs?

Answer 23

o Compression stockings
o Use of intermittent pneumatic compression devices
o Encouragement of early mobilization + leg exercises
o LMWH’s in post-surgical
o Lifestyle changes: weight loss, smoking cessation, regular exercise

Question 24

Tx of clots?

Answer 24

Anticoag only for prevention…cannot dissolve clot

Thrombolytics to eliminate venous obstruction, maintain venous patency, & prevent postthrombotic syndrome by early removal of thrombus

Endovascular management when can’t use anticoag or thrombolytic tx or case is sever – mechanical method of clot removal

Question 25

Possible complication of heparin?

Answer 25

Thrombocytopenia

sudden >30% dec in platelet count – can be d/t long term use o fractionated heparin

Question 26

Contraindications for anticoagulant tx

Answer 26

o	Lack of pt cooperation
o	GI, GU, resp, reproductive bleeding
o	Hemorrhagic blood dyscrasias
o	Aneurysms
o	Severe trauma
o	Alcoholism
o	Recent or impending sx of eye, spinal cord, or brain
o	Severe hepatic or renal disease
o	Recent cerebrovascular hemorrhage
o	Infections
o	Open ulcerative wounds
o	Occupations with sig risk of injury
o	Recent childbirth

Question 27

How is unfractioned heparin administered? (route)

Answer 27

Administered subcut to prevent DVT or continuous IV infusion for 5 days to prevent extension of thrombus + devel of new thrombus (low continuous does to prevent hemorrhage)

Question 28

WHy are LWMH’s only administered once daily typically?

How is dosing determined?

What do they do?

how are they advantageous in comparison to unfractioned heparins?

Answer 28

• Have longer half lives than unfractioned, so can be given in 1-2 doses/day
• Dose according to weight
• Prevent ext of throbus + dev of new
• Assoc with fewer bleeding complications + lower risk of heparin-induced thrombocytopenia (HIT) than unfractionated but more expensive

Question 29

Route for warfarin?
Typically used for?

Is therapeutic window large? Target range?

Answer 29

Oral
indicated for extended anticoagulant tx

• Has narrow therapeutic window and slow onset – tx usually initiated in combo with parenteral anticoag’s until therapeutic effect of warfarin established
• Therapeutic range = PT 1.5-2x, or INR is 2.0 to 3.0

Question 30

How does the risk for bleeding compare for thrombolytics and heparin?

Answer 30

Thrombolytic therapy causes 3X inc in bleeding compared to heparin

Question 31

D-dimer test?

Answer 31

D-dimer (or D dimer) is a fibrin degradation product (or FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis.