Thrombus (blood clot) a fibrin network made up of platelets, red blood cells, and white blood cells that
forms in an artery or vein.
Phlebitis – inflammation of a vein wall.
Thrombophlebitis – thrombus formation with inflammation of the vein wall.
Phlebothrombosis – thrombus formation with no inflammation of the vein wall.
Superficial Thrombophlebitis – thrombus formation with inflammation of the vein wall in a superficial
vein.
Deep Vein Thrombophlebitis/Deep Vein Thrombosis (DVT) – thrombus formation in a deep vein (with
or without inflammation of the vein wall). DVT is of greater significance than superficial
thrombophlebitis because embolization of thrombi from deep veins to the lungs (pulmonary
embolus) may be fatal. The greatest danger of thrombophlebitis is pulmonary embolism – all or part of a
thrombus can detach from vein wall and migrate to the lungs.
Three important factors cause venous thrombus formation:
Virchow’s Triad
1.
Venous Stasis (stoppage of venous blood flow or ↓ in venous flow ) occurs in an immobilized limb
(muscles are inactive) – prolonged immobility, bed rest, leg cast, traction, post-op patients;
pregnancy; obesity; advanced age (more than 60 years old); patients undergoing surgery (especially
abdominal or pelvic surgery); sluggish peripheral circulation (CHF, dehydration); incompetent
valves (varicose veins)
2.
Damage to the vein wall (intimal or endothelial layer) creates a site for clot formation. Vein wall
damage can result from infection, intravenous infusion of medications, venipuncture, traumatic
injury (fracturis), orthopedic procedures on legs, History of DVT/venous problems.
3.
Hypercoagulability of blood. Factors that can cause blood to coagulate faster than normal include
oral contraceptives (especially those containing estrogen and in women who smoke and > 35 years
old), cigarette smoking, dehydration, abrupt withdrawal of anticoagulant medications – rebound
effect, blood disorders such as Malignancy/cancer like polycythemia vera (leads to sluggish blood,
thick with RBCs) and anti-thrombin III deficiency. (Antithrombin III is a circulating anti-coagulant
which inactivates thrombin and other clotting factors. Therefore ↓ amounts would ↑ risk of
thrombus formation.)
Most venous thrombi form in the legs, usually in the calves. Superficial Thrombophlebitis clinical
manifestations produces pain or tenderness along course of vein, heat/warmth, redness, and swelling of
the involved area. (↑ WBC) (The four cardinal signs of inflammation.) On palpitation, the vein may feel
like a firm, subcutaneous cord (a palpable, visible, firm subcutaneous cordlike vein).
A mild systemic temperature elevation and leukocytosis may be present.
Therapeutic Management of Superficial Thrombophlebitis
Goals:
 Reduce inflammation and prevent emboli formation; increase venous return to the heart,
decreasing venous pressure. Bed rest with affected extremity elevated above heart level to
decrease swelling and enhance venous return. Bed rest to prevent dislodgement of thrombus.
 Warm, moist compresses to relieve pain and reduce inflammation. Mild oral analgesics
(acetaminophen) to relieve pain. For more severe pain, a nonsteroidal anti-inflammatory agent
(ibuprofen) to relieve pain and inflammation.
 Elastic compression stockings after acute stage when patient becomes ambulatory. Elastic
stockings compress superficial veins, reducing pooling of venous blood and enhancing venous
return to the heart.
 Anticoagulant therapy is usually not indicated for superficial thrombophlebitis.
 The risk of superficial venous thrombi dislodging and causing emboli is very low because the
majority of them adhere firmly to the vein wall and undergo spontaneous lyses.
Diagnostic Studies in Deep Vein
Thrombophlebitis
Noninvasive venous studies
Doppler Ultrasound – common
noninvasive test to measure blood flow
through blood vessels (arteries and
veins). In DVT, determines venous
blood flow in deep veins. In Doppler
ultrasound, a probe transmits highfrequency sound waves through the skin
toward veins. The sound waves strike
the moving red blood cells and are
transmitted back to the probe, producing
audible tone. Normal venous blood flow
creates a roaring sound. In the patient
with DVT, the sound of venous blood
flow is diminished or absent.
TPA – tissue plasminogen activator – dissolves clots, bodies natural fibrinolytic
Duplex venous scanning or imaging (noninvasive) test is usually done with Doppler flow studies.
Doppler scanning produces a three-dimensional view of the veins on a monitor screen, allowing examiner
to view both vessel and any thrombus, thrombi.
D-dimer test: A blood test to measure fibrin degradation fragments generated by fibrinolysis. Elevated
D-dimer levels indicate a thrombotic process, but aren’t specific to DVT. (D-dimer is produced by action
of plasmin of fibrin clot.)
Impedance Plethysmography measures venous changes in the limbs. The test uses a blood pressure cuff
wrapped around the patient’s thigh and inflated (50 to 60 mm Hg) to occlude venous blood flow from the
calf. In the normal patient, venous blood volume in the calf increases markedly as blood becomes trapped
below the cuff. If a DVT is present, venous volume won’t increase as much because blood is already
trapped in the calf. When the pressure applied by the thigh cuff is released, venous outflow is measured.
Normally, venous volume falls dramatically as the trapped blood surges upward. In the leg with DVT,
venous volume remains much the same.
INVASIVE PROCEDURE VENOGRAPHY is the most definitive test for diagnosing DVT but it
carries several risks (eg, allergic reaction to dye – contrast medium-phlebitis) and so should only be done
is the patient has signs and symptoms of DVT, but the results of noninvasive studies are ambiguous.
Procedures involves injecting contrast media into bloodstream, followed by x-rays to identify location of
clot.
**Edema in extremities is a vein problem, never an artery problem.
DEEP VEIN THROMBOPHLEBITIS (DVT)
Clinical Manifestations
Once a thrombus becomes large enough to completely obstruct blood flow through a vein, signs and
symptoms develop. The first sign is usually edemal swelling of affected extremity. The amount of
swelling can be determined by measuring extremity (ankle, calf, and inner thigh) circumference at various
levels with a tape measure, compare one extremity to the other by measuring the circumference of each at
the same level for size differences. Inspect legs from groin to feet, noting any unilateral or bilateral
changes. Compare one leg to the other.
The skin over the affected area may become warmer. There may also be erythema (redness) in the
affected area. The patient may complain of a tight or heavy sensation in the limb, heaviness in the
affected limb and pain or tenderness over involved vein or palpation. Malaise and fever sometimes occur.
A positive Homan’s sign (calf pain upon dorsification of the foot) is a classic but unreliable sign for DVT
because it can be elicited in any painful condition of the calf. Diminished or absent Doppler flow reading
over veins in affected extremity.
Management Goals: Prevent existing thrombi from becoming emboli. Prevent new thrombi from
forming increase venous return to the heart; decrease venous pressure. Bed rest to prevent clot
dislodgement. Bed rest is usually required for about 5 to 7 days after DVT to give the clot time to adhere
to the vein wall so it won’t embolize.
Elevate the affected extremity above heart level to reduce swelling (↓ venous pressure) and enhance
venous return (prevents venous stasis and the formation of new thrombi)
Elevate the patient’s legs by elevating the foot of the bed six inches on blocks. Avoid placing pillows
under patient’s knees and use of knee gatch to prevent compression of the popliteal vein and obstruction
of venous blood flow.
Do not elevate the head of the bed more than 30 degrees to prevent inguinal congestion (consult doctor
regarding degree HOB should be elevated).
Apply warm, moist, compresses to affected extremity to relieve pain and reduce inflammation; if ordered,
administer mild oral analgesics (eg, acetaminophen) to relieve pain. Measure and record circumference of
extremity daily. Compare bilaterally and with previous measurements. Assess extremity color,
temperature, pulses, complaint of pain.
**Don’t give Tylenol with Coumadin or Warfarin.
Do not exercise affected extremity during acute phase of DVT to prevent clot dislodgement. Instruct
and assist patient to move affected extremity slowly and cautiously.
The unaffected extremity should be exercised actively to promote venous blood flow.
Never rub or massage affected extremity – could dislodge clot.
To protect affected extremity from trauma and pressure, use an air mattress, sheepskin, heelpads, and a
bed cradle or foot board.
Caution patient to avoid activities that create a Valsalva maneuver (eg, straining to have bowel
movement [stool softener], holding breath while moving in bed [provide trapeze]). Valsalva maneuver ↑
intra-abdominal pressure, ↓ venous return, ↑ venous pressure. Instruct patient to perform deep
breathing exercises to promote venous return.
Maintain adequate fluid intake – two to three liters a day unless contraindication – to prevent
dehydration. Elastic compression bandages /Ace bandages are usually prescribed to promote venous
return and decrease leg swelling. Bandages are applied from toes up with uniform/even pressure. Should
be rewrapped at least once during each shift; check for circulatory, motor, and neurologic functions in
extremity because an improperly wrapped bandage can have a tourniquet effect. Once swelling has
subsided, patient can be measured for an elastic support stocking.
SUMMARY
Non-invasive test for thrombophlebitis:
1. Doppler ultrasound
2. D-dimer test (degraded fibrin fragments)
3. Plethysmography (cuff around thigh)
Invasive tests for thrombophlebitis:
1. Venography (risks = allergy to dye.