DVT Flashcards
DVT & PE together =
= venous thromboembolism (VTE)
T/F DVT/PE rarely go undetected
False
DVT + PE often clinically silent (so incidence underestimated)
Risk factors for DVT:
*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
S&S for DVT?
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
When does venus stasis result?
immobilization, obesity, hx of variscosities, spinal cord injury, age (
Those factors that r/t endothelial damage as a risk factor for DVT?
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
Which conditions cause altered coagulation?
cancer, pregnancy, oral contraceptive use, protein C or S deficiency, antithrombin III deficiency, polycythemia, septicemia, elevated factors II, VIII, IX, XI
Why are those who are pregnant more at risk of DVT?
inc in clotting factors, can least up to 8 weeks postpartum
Does DVT only occur in the deep veins?
Can occur in both superficial + deep veins, most often in lower extremities (but can occur anywhere)
How does repetitive motion result in clots?
• Repetitive motion (as in competitive swimmers, construction workers) causes irritation of vessel wall → inflm → thrombosis = effort thrombosis
What is recanalization and how does it r/t DVT?
• After DVT, recanalization (reestablishment of lumen of vessel) typically occurs
phlegmasia cerulea dolens
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
What will you see with clots in superficial veins?
Are they as dangerous? How to treat?
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
Key concerns in DVT assessment:
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
Complications of DVT?
- 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
Characteristics of the deep veins?
thinner walls, less muscle in media, lie parallel to arteries (have same names)
Important labs for DVT?
PTT, PT-INR D-Dimer (not reliable) ACT (?) Hb + HCt platelet count fibrinogen levels
Nursing interventiosn for DVT?
- 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
What is often the first sign of too high dosage of anticoagulant?
blood in urine often first sign of excessive dosage
exmined by microscopy,
What are graduated compression stockings?
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
What is given to reverse the effects of heparin?
• Protamine sulfate given IV to reverse effects of heparin (risk bradycardia + hypotension…administer slowly!) – less but still some effectiveness with LMWH
How to reverse warfarin?
Vit K
Prevention of DVTs?
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
Tx of clots?
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
