deep vein thrombosis
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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
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