DEEP VEIN THROMBOSIS [DVT]

Introduction

Deep vein thrombosis, or deep venous thrombosis, (DVT) is the formation of a blood clot (thrombus) in

a deep vein, predominantly in the legs. Venous thromboses are comprised mainly of fibrin and red blood cells.

DVT can occur in the upper extremities, cerebral sinuses, hepatic, and retinal veins.

Definition

Deep vein thrombosis (DVT) is a condition in which a blood clot (thrombus) forms in one or more of the

deep veins in your body, usually in your legs or pelvic area. Deep vein thrombosis can cause leg pain, but often

occurs without any symptoms.

Causes

The three factors discovered by German pathologist named as Virchow's triad - Venous stasis, Vein wall

trauma/ dilation (changes in the endothelial blood vessel lining ) and hypercoagulability

Venous stasis: immobility reduces the effectiveness of the calf muscle pump and can lead to stasis

(slowing of blood flow) and pooling of blood behind the valve cusps;

Vein wall trauma/dilation: local trauma (for example, orthopaedic surgery or leg fracture) to

the endothelial lining of the vein wall activates clotting by triggering the release of tissue factor.

Venous dilation, which may occur intraoperatively, can cause endothelial damage resulting in

the exposure of collagen and activation of clotting;

Hypercoagulability: a variety of hereditary and acquired causes of increased coagulability, such

as pregnancy, malignancy, and thrombophilia.

DVT is generally caused by a combination of two or three underlying conditions:

Slow or sluggish blood flow through a deep vein

Tendency for a person’s blood to clot quickly

Irritation, inflammation or injury to the inner lining of the vein

Other related causes include

o activation of immune system components,

o the state of microparticles in the blood,

o the concentration of oxygen,

o possible platelet activation.

Risk factors

Various risk factors contribute to DVT, though many at high risk never develop it.

STRONG RISK FACTORS MODERATE RISK FACTORS WEAK RISK FACTORS

• Fracture (hip or leg)

• Hip or knee replacement

• Major general surgery

• Major trauma

• Spinal cord injury

• Arthroscopic knee surgery

• Central venous lines

• Congestive heart failure

• Respiratory failure Hormone

replacement therapy

• Intravenous drug abuse

• Malignancy

• Oral contraceptives

• Paralytic stroke

• Pregnancy/postpartum

• Previous venous

thromboembolism

• Thrombophilia

• Bed rest <3 days

• Immobility due to sitting, such

as in prolonged car or air travel

• Increasing age

• Laparoscopic surgery

• Obesity

• Varicose veins

Symptoms

Calf pain and/or tenderness;

Swelling with pitting oedema;

Swelling below the knee in distal DVT and up to the groin in proximal DVT;

Increased skin temperature;

Superficial venous dilation;

Cyanosis can occur with severe obstruction. Change in color (blue, red or very pale)

Fullness of the veins just beneath the skin

Even patients with extensive venous thrombosis may have minimal leg symptoms, while pain, tenderness,

and swelling of the leg may be caused by other disorders The most common symptom is leg pain and tenderness

in the calf muscles.

Diagnosis

Pre-test probability

HISTORY

● Paralysis, paresis or recent plaster immobilisation

● Bedridden for >3 days

● Major surgery in last 4 weeks

● Recent airline flight >4 hours

● Active cancer treatment in the past six months or palliative cancer treatment

● Strong family history of DVT (two or more affected first-degree relatives)

ON EXAMINATION

● Entire leg swollen

● Symptomatic calf more than 3cm larger than other leg measured 10cm below tibial tuberosity

● Tenderness along deep venous system

● Collateral superficial veins (non varicose)

[Score 1 point for each of the following and Subtract 2 points if another diagnosis is more likely]

[3 = High risk; 1–2 = Moderate risk; 0 = Low risk]

D-dimer

A specific blood test may also be performed to measure “D-dimer” which is a sign of recent

clotting. When this test is negative, it is unlikely that DVT has occurred. 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. It is so named because it contains two crosslinked D fragments of

the fibrin protein

Ultrasonography

Duplex ultrasonography is a non-invasive method of detecting DVT. Proximal DVT can be

detected with a sensitivity and specificity of 96 per cent and 98 per cent respectively It is, however, less

sensitive for distal DVT and pelvic DVT.

Venography

This is the ‘gold-standard’ investigation for DVT but due to its invasive nature it is no longer a

first-line investigation. Radiopaque contrast is injected into a dorsal foot vein to visualise thrombi under

X-ray control. The procedure carries a small risk of venous thrombosis or allergic reaction to the dye, and

may be technically difficult in patients who have poor venous access

Plethysmography

This non-invasive method records changes in limb size due to accumulation of tissue fluid or

pooled blood. Plethysmography is of limited value in the detection of older thrombi or in cases of non-

occlusive thromboses.

Magnetic resonance direct thrombus imaging

This is a novel non-invasive technique in which the thrombus is visualised by the detection of

methaemoglobin. The technique detects recent thrombi, and is therefore also useful for the diagnosis of

recurrent DVT.

Complications of DVT

After diagnosis of DVT the thrombus may dissolve without causing any problems but in a

minority of patients Pulmonary Embolism may occur, which can be fatal. It occurs when a part of the

thrombus becomes detached from the vein wall and lodges in the pulmonary circulation. It can cause

respiratory difficulties such as shortness of breath, pain on inspiration, and haemoptysis.

Post-thrombotic syndrome is a long-term complication of DVT. It occurs due to damage and

incompetence of venous valves causing blood to pool in the lower leg. The clinical signs include chronic

swelling and skin changes in the affected limb.

Recurrent DVT or Pulmonary Embolism is common, particularly after idiopathic thrombosis or

in the presence of persisting risk factors.

Venous leg ulcers develop as a result of DVT. These chronic wounds can make a significant

impact on quality of life as well as on health care resources

Treatment

The objectives of treatment for DVT include the prevention of: local thrombus extension; embolisation; and

recurrent DVT.

Mobilisation Mobile patients with acute proximal DVT treated with LMWH should be encouraged to walk with

compression stockings. Pain and swelling resolve significantly faster, with no evidence of an associated

increase in risk of pulmonary embolism.

Anticoagulation Anticoagulation with heparin and warfarin is the standard treatment for DVT; LMWH has been

demonstrated to be safe, effective, and convenient, and has allowed patients to be managed in an outpatient

setting

Oral anticoagulants such as warfarin inhibit the vitamin K-dependent clotting factors.

Compression stockings Once a patient has been diagnosed with a DVT, compression stockings (Class I, II, or III) are applied

to reduce the risk of recurrence and the development of post-thrombotic syndrome. Some manufacturers of

high compression stockings (20–40mmHg at the ankle: Class I, II, and III) recommend that an

ankle:brachial ratio check (the ratio of ankle systolic pressure to highest brachial systolic pressure) should

be performed before fitting.

Thrombolysis

The health care providers may also recommend thrombolysis, using an intravenous agent that

dissolves clots. The clotbuster is injected slowly through a catheter with many tiny holes into the

area of the DVT, much like a soaker hose. Sometimes a tiny vacuum cleaner is used to suck out

the softened clot. Once the clot is gone, balloon angioplasty or stenting may be necessary to

open the narrowed vein, but this is common only in the iliac veins, located in the pelvic area.

With this approach, the patient will also need anticoagulant medication (heparin) to prevent new

blood-clot formation while the existing clot is being dissolved.

Surgical intervention

For a few patients who have valid reasons for clot removal but for whom clot-dissolving drugs

cannot be used, extraction of the clot, through a small incision at the groin, may be recommended. Both

approaches are designed to remove the clot and restore the venous system to normal, but they involve

additional risk and expense and therefore are applied selectively by the appropriate vascular specialist.

Prevention of DVT The basis of DVT prophylaxis is to target the triad of predisposing factors: venous stasis; vein wall

trauma/dilation; and hypercoagulability.

Mobilisation and breathing exercises Nurses can encourage mobilisation and leg exercises in at-risk patients in order to activate

the calf muscle pump. Breathing exercises will also help venous return. Patients should be advised

to observe for signs and symptoms that suggest DVT and inform nurses if concerned.

Antiembolism stockings Antiembolism stockings (AES) provide continuous stimulation of linear blood flow, prevent

venous dilation and stimulate endothelial fibrinolytic activity

The nurse’s role is to assess for contraindications to wearing AES by physical assessment

and clinical history and to measure and fit the correct stockings according to the information

supplied by the manufacturer. The patient’s skin integrity should be checked regularly and the

patient should be given written and verbal information on how to wear and care for AES. The patient

should be told that:

• Stockings should be smooth when fitted;

• The toe hole should lie underneath the toes;

• The heel patch should be in the correct position;

• The thigh gusset should be on the inner thigh;

• Rolling down the stocking may have a tourniquet effect.

Patients should be asked to report any numbness or tingling, which may suggest arterial impairment.

Anticoagulants Anticoagulants such as low-molecular-weight heparin (LMWH) increase the action of

antithrombin and inhibit a number of coagulation proteins. LMWH can be administered in a

prophylactic dose, usually via subcutaneous injection, with a predictable anticoagulant response. In

moderate-risk patients use of AES may be combined with anticoagulants to minimise risk.

Patients require careful observation as anticoagulants can cause bleeding, and any side-

effects should be reported. An obvious drop in the platelet count may indicate heparin-induced

thrombocytopaenia (HIT). Nurses should observe for local reactions at injection sites, which may

necessitate switching to another brand of LMWH.

Intermittent pneumatic compression Intermittent pneumatic compression (IPC) is an established method of DVT prophylaxis

with no risk of haemorrhagic complications. There is a variety of devices on the market ranging

from calf and thigh cuffs to foot pumps. They may be combined with the use of AES and LMWH

in high-risk patients.

Some Tips to Avoid DVT

Do not sit for long periods of time

Elevate legs if you are sitting for moderate periods of time

If you are on an airplane for more than four hours-get up

and walk in the aisles, pump your feet up and down

If you are flying, drink plenty of non-alcoholic beverages

Keep hydrated-drink six glasses of water a day

Talk to your doctor about the need for medications or graduated

elastic compression stockings for long airplane flights

If you have varicose veins, wear support hose (especially if pregnant)

Do not wear constricting garments around the legs or waist (elastic bands or garters)

Nursing Priorities

1. Maintain/enhance tissue perfusion, facilitate resolution of thrombus.

2. Promote optimal comfort.

3. Prevent complications.

4. Provide information about disease process/prognosis and treatment regimen.

Nursing Care Plan

sing diagnosis Outcome Plan of action Rationale

Ineffective peripheral

Tissue Perfusion • May be related to

• Decreased blood

flow/venous stasis

(partial or complete

venous obstruction)

Possibly evidenced by • Tissue edema, pain

• Diminished

peripheral pulses,

slow/diminished

capillary refill

• Skin color changes

(pallor, erythema)

CLIENT WILL:

Tissue Perfusion:

Peripheral Demonstrate

improved perfusion as

evidenced by peripheral

pulses present/equal, skin

color and temperature

normal, absence of

edema.

• Engage in

behaviors/action

s to enhance

tissue perfusion.

• Display

increasing

tolerance to

activity.

• Evaluate circulatory and neurologic

studies of involved extremity—both

sensory and motor.

• Inspect for skin color and temperature

changes, as well as edema (from groin

to foot).

• Note symmetry of calves; measure and

record calf circumference & Report

proximal progression of inflammatory

process, traveling pain.

• Examine extremity for obviously

prominent veins. Palpate gently for

local tissue tension, stretched skin,

knots/bumps along course of vein.

• Assess capillary refill and check for

Homans’ sign.

• Promote early ambulation.

• Elevate legs when in bed or chair, as

indicated.

• Symptoms help distinguish between

thrombophlebitis and DVT.

• Redness, heat, tenderness, and

localized edema are characteristic of

superficial involvement.

• Unilateral edema is one of the most

reliable physical findings in DVT.

Calf vein involvement is associated

with absence of edema; femoral vein

involvement is associated with mild

to moderate edema; iliofemoral vein

thrombosis is characterized by severe

edema.

• Distention of superficial veins can

occur in DVT because of backflow

through communicating veins.

Thrombophlebitis in superficial veins

may be visible or palpable.

• Diminished capillary refill usually

present in DVT. Positive Homans’

sign (deep calf pain in affected leg

upon dorsiflexion of foot) is a classic

but unreliable sign because many

clients with DVT do not have a

positive Homans’ sign.

• Short frequent walks are determined

to be better for extremeties and

prevention of pulmonary

complications than one long walk. If

client is confined to bed, ensure

range-of-motion exercises.

• Reduces tissue swelling and rapidly

empties superficial and tibial veins,

preventing overdistention and thereby

increasing venous return.

• Initiate active or passive exercises

while in bed (e.g., flex/extend/rotate

foot periodically). Assist with gradual

resumption of ambulation (e.g., walking

10 min/hr) as soon as client is permitted

out of bed.

• Caution client to avoid crossing legs or

hyperflexion at knee (seated position

with legs dangling, or lying in jackknife

position).

• Instruct client to avoid rubbing/

massaging the affected extremity.

• Encourage deep-breathing exercises.

• Increase fluid intake to at least 2000

mL/day, within cardiac tolerance.

• Apply warm, moist compresses or heat

cradle to affected extremity if indicated.

• Administer anticoagulants,

e.g.:heparin sodium, or low-

molecular-weight heparin (LMWH) preparations, such as enorxaparin

(Lovenox), dalteparin (Fragmin),

tinzaparin (Innohep) via continuous or

intermittent IV, intermittent

subcutaneous (SC) injections, followed

by oral coumarin derivatives, e.g.,

warfarin (Coumadin) or dicumarol

(Sintrom);

• These measures are designed to

increase venous return from lower

extremities and reduce venous stasis,

as well as improve general muscle

tone/strength. They also promote

normal organ function and enhance

general well-being.

• Physical restriction of circulation

impairs blood flow and increases

venous stasis in pelvic, popliteal, and

leg vessels, thus increasing swelling

and discomfort.

• This activity potentiates risk of

fragmenting/dislodging thrombus,

causing embolization, and

increasing risk of complications.

• Increases negative pressure in

thorax, which assists in emptying

large veins.

• Dehydration increases blood

viscosity and venous stasis,

predisposing to thrombus formation.

• May be prescribed to promote

vasodilation and venous return and

resolution of local edema.

• Heparin may be used initially because

of its prompt, predictable,

antagonistic action on thrombin as it

is formed and also because it

removes activated coagulation

factors XII, XI, IX, and X (intrinsic

pathway), preventing further clot

formation. LMWH is the anticogulant

of choice after major orthopedic

sugery and major trauma due to a

lower risk of bleeding, more

predictable dose response and longer

half-life than heparin. Coumadin has

a potent depressant effect on liver

• Thrombolytic agents; e.g.,

streptokinase, urokinase.

• Monitor laboratory studies as

indicated:

PT, PTT, aPTT

• Platelet count, platelet

function/aggregation test, antiheparin

antibody assay.

• Apply/regulate graduated compression

stockings, intermittent pneumatic

compression if indicated.

• Apply elastic support hose following

acute phase. Take care to avoid

tourniquet effect.

• Prepare for surgical intervention when

indicated.

formation of prothrombin from

vitamin K and impairs formation of

factors VII, IX, and X (extrinsic

pathway).

• May be used in hemodynamically

unstable client with PE or massive

DVT to reduce risk of developing

PE, or the presence of valvular

damage and/or chronic venous

insufficiency. Heparin is usually

begun several hours after the

completion of thrombolytic therapy.

• Monitors anticoagulant therapy and

presence of risk factors; e.g.,

hemoconcentration and dehydration, which potentiate clot formation

• On occasion, platelet count may

decrease as a result of an immune

reaction leading to platelet

aggregation or the formation of

“white clots.” • Sequential compression devices may

be used to improve blood flow

velocity and empty vessels by

providing artificial muscle-pumping

action.

• Properly fitted support hose are

useful (once ambulation has begun)

to minimize or delay development of

postphlebotic syndrome &

distributed pressure over entire

surface of calves and thighs to reduce

the caliber of superficial veins and

increase blood flow to deep veins.

• Thrombectomy (excision of

thrombus) is occasionally necessary

if inflammation extends proximally

or circulation is severely restricted.

Multiple/recurrent thrombotic

episodes unresponsive to medical

treatment (or when anticoagulant

therapy is contraindicated) may

require insertion of a vena caval

screen/umbrella.

Acute Pain/[Discomfort]

May be related to • Diminished arterial

circulation and

oxygenation of tissues

with

production/accumulation

of lactic acid in tissues

• Inflammatory process

Possibly evidenced by • Reports of pain,

tenderness,

aching/burning

• Guarding of affected

limb

• Restlessness,

distraction behaviors

CLIENT WILL:

Pain Control • Report that

pain/discomfort is

alleviated or controlled.

• Verbalize methods that

provide relief.

• Display relaxed manner;

be able to sleep/rest and

engage in desired activity.

• Assess degree and characteristics of

discomfort/pain. Palpate leg with

caution.

• Maintain bedrest during acute phase.

• Elevate affected extremity.

• Provide foot cradle.

• Encourage client to change position

frequently.

• Monitor vital signs, noting elevated

temperature.

• Investigate reports of sudden and/or

sharp chest pain, accompanied by

dyspnea, tachycardia, and

apprehension, or development of a new

pain with signs of another site of

vascular involvement.

• Administer medications, as indicated:

• Degree of pain is directly related to

extent of circulatory deficit,

inflammatory process, degree of

tissue ischemia, and extent of

edema associated with thrombus

development. Changes in

characteristics of pain may indicate

progression of problem/development

of complications.

• Reduces discomfort associated with

muscle contraction and movement.

• Encourages venous return to

facilitate circulation, reducing

stasis/edema formation.

• Cradle keeps pressure of bedclothes

off the affected leg, thereby

reducing pressure discomfort.

• Decreases/prevents muscle fatigue,

helps minimize muscle spasm,

maximizes circulation to tissues.

• Elevations in heart rate may

indicate increased pain/discomfort or

occur in response to fever and

inflammatory process. Fever can

also increase client’s discomfort.

• These signs/symptoms suggest the

presence of pulmonary emboli as a

complication of DVT or peripheral

arterial occlusion associated with

heparin-induced thrombocytopenia

and thrombosis (HITT). Both

conditions require prompt medical

evaluation and treatment.

Analgesics (narcotic/nonnarcotic);

Antipyretic; e.g., acetaminophen

(Tylenol).

• Apply moist heat to extremity if

indicated

• Relieves pain and decreases muscle

tension.

• Reduces fever and inflammation.

• Causes vasodilation, which

increases circulation, relaxes

muscles, and may stimulate release

of natural endorphins.

Deficient Knowledge

[Learning Need]

regarding condition,

treatment program, self-

care, and discharge needs Related to

• Lack of exposure or recall

• Misinterpretation of

information

• Unfamiliarity with

information resources

Possibly evidenced by • Request for

information, statement

of misconception

• Inaccurate follow-

through of instructions

• Development of

preventable

complications

CLIENT WILL:

Knowledge: Disease

Process

• Verbalize

understanding of

disease process,

treatment regimen,

and limitations.

• Participate in

learning process.

• Identify

signs/symptoms

requiring medical

evaluation.

Knowledge: Treatment

Regimen

• Correctly perform

therapeutic actions

and explain reasons

for actions.

Disease Process

• Review pathophysiology of condition

and signs/symptoms of possible

complications; e.g., pulmonary

emboli, chronic venous insufficiency,

venous stasis ulcers (postphlebitic

syndrome).

• Explain purpose of activity

restrictions and need for balance

between activity/rest.

• Establish appropriate exercise /

activity program.

• Problem-solve solutions to

predisposing factors that may be

present; e.g., employment that

requires prolonged standing/sitting,

wearing restrictive clothing

(girdles/garters), use of oral

contraceptives, obesity, prolonged

bed rest/immobility, dehydration.

• Recommend sitting with feet

touching the floor, avoiding crossing

of legs.

• Review purpose and demonstrate

correct application/ removal of

antiembolic hose.

• Provides a knowledge base from

which client can make informed

choices and understand/identify

healthcare needs. Up to 33%

experience a recurrence of DVT.

• Rest reduces oxygen and nutrient

needs of compromised tissues and

decreases risk of fragmentation of

thrombosis. Balancing rest with

activity prevents exhaustion and

further impairment of cellular

perfusion.

• Aids in developing collateral

circulation, enhances venous

return, and prevents recurrence.

• Actively involves client in

identifying and initiating

lifestyle/behavior changes to

promote health and prevent

recurrence of condition

/development of complications.

• Prevents excess pressure on the

popliteal space.

• Understanding may enhance

cooperation with prescribed therapy

• Instruct in meticulous skin care of

lower extremities; e.g.,

prevent/promptly treat breaks in skin

and report development of

lesions/ulcers or changes in skin

color.

Teaching: Prescribed Medication • Discuss purpose, dosage of

anticoagulant. Emphasize importance

of taking drug as prescribed.

• Identify safety precautions; e.g., use

of soft toothbrush, electric razor for

shaving, gloves for gardening,

avoiding sharp objects (including

toothpicks), walking barefoot,

engaging in rough sports /activities, or

forceful blowing of nose.

• Review client’s usual medications and

foods when on oral anticoagulants,

stress need to read ingredient labels of

OTC drugs and herbal supplements,

and discuss use with healthcare

provider prior to starting new

medications.

• Identify untoward anticoagulant

effects requiring medical attention; e.g., bleeding from mucous membranes

(nose, gums), continued oozing from

and prevent improper/ineffective use.

• Chronic venous congestion/

postphlebitic syndrome may develop

(especially in presence of severe

vascular involvement and/or

recurrent episodes), potentiating risk

of stasis ulcers/infection.

• Promotes client safety by reducing

risk of inadequate therapeutic

response/ deleterious side effects.

• Reduces the risk of traumatic

injury, which potentiates

bleeding/clot formation.

• Warfarin (Coumadin) interacts with

many foods and drugs, either

increasing or decreasing the

anticoaglant effect. Salicylates and

excess alcohol decrease prothrombin

activity, whereas vitamin K

(multivitamins, bananas, leafy green

vegetables) increases prothrombin

activity, and can cause a higher or

lower INR, possibly outside of the

therapeutic range. Barbiturates

increase metabolism of coumarin

drugs; antibiotics alter intestinal

flora and may interfere with vitamin

K synthesis.

• Early detection of deleterious effects

of therapy (prolongation of clotting

time) allows for timely intervention

cuts/punctures, severe bruising after

minimal trauma, development of

petechiae.

• Stress importance of medical follow-

up/laboratory testing.

• Encourage wearing of medical

identification bracelet/ tag, as

indicated.

and may prevent serious

complications.

• Understanding that close supervision

of anticoagulant therapy is

necessary (therapeutic dosage range

is narrow and complications may be

deadly) promotes client

participation.

• Alerts emergency healthcare

providers to history of thrombotic

problems and/or current use of/or

need for anticoagulants (e.g.,

prophylactic before and after any

procedure or event with an increased

risk of venous thromboembolism.

Conclusion DVT can be associated with significant morbidity. Nurses should focus on prevention by the early recognition and adequate prophylaxis of those at increased

risk. Patients should be actively involved in their care wherever possible. An awareness of diagnostic and treatment strategies will enable nurses to inform

patients. This will help to improve both concordance with treatment and disease outcome.

*************

Topic presentation

On

Deep vein thrombosis {dvt} & its management

JOHN JACOB