DEEP VEIN THROMBOSIS (DVT)

1. Definition of Deep Vein Thrombosis (DVT):

Deep Vein Thrombosis is a medical condition characterized by the formation of a blood clot
(thrombus) in one or more of the deep veins, most commonly occurring in the lower legs,
thighs, or pelvis. DVT can partially or completely block blood flow in the affected vein,
potentially leading to serious complications if left untreated.

2. Etiology (Causes) of DVT:

a) Venous stasis (slowed blood flow):

• Prolonged immobility (e.g., long flights, bed rest)

• Paralysis
• Varicose veins

b) Hypercoagulability (increased tendency for blood to clot):

• Genetic factors (e.g., Factor V Leiden, Prothrombin gene mutation)

• Hormone-related (e.g., oral contraceptives, pregnancy)
• Cancer
• Obesity

c) Endothelial injury (damage to blood vessel walls):

• Surgery
• Trauma
• Intravenous catheterization

Additional risk factors include:

• Age (risk increases with age)

• Previous history of DVT
• Smoking
• Inflammatory bowel disease
• Heart failure
• Nephrotic syndrome

3. Pathophysiology of DVT:

a) Initiation of clot formation:

• Tissue factor exposure due to endothelial damage

• Activation of the coagulation cascade

b) Platelet activation and aggregation:

• Platelets adhere to damaged endothelium

• Release of pro-coagulant factors
c) Fibrin formation:

• Conversion of fibrinogen to fibrin

• Stabilization of the growing thrombus

d) Propagation of the thrombus:

• Continued activation of coagulation factors

• Incorporation of red blood cells into the clot

e) Inflammatory response:

• Release of inflammatory mediators

• Recruitment of leukocytes

f) Impairment of venous return:

• Partial or complete occlusion of the vein

• Increased venous pressure distal to the thrombus

g) Valvular damage:

• Potential long-term damage to venous valves

h) Thrombus organization and recanalization:

• Gradual replacement of the clot with fibrous tissue

• Potential development of collateral circulation

i) Risk of embolization:

• Possibility of thrombus fragmentation

• Potential for pulmonary embolism

j) Activation of fibrinolysis:

• Natural attempt to break down the clot

• Balance between clot formation and dissolution

k) Endothelial dysfunction:

• Reduced production of natural anticoagulants

• Impaired fibrinolytic activity

l) Venous wall remodeling:

• Thickening of venous walls

• Potential for post-thrombotic syndrome
Symptoms of DVT:

1. Swelling:
o Usually unilateral, affecting the entire leg or just below the knee
o Can be sudden or gradual
2. Pain or tenderness:
o Often described as a cramping or soreness in the calf
o May worsen when standing or walking
3. Warmth:
o The affected area may feel warmer than surrounding areas
4. Skin color changes:
o Redness or discoloration of the affected limb
o Sometimes a bluish or whitish hue
5. Visible surface veins:
o Dilated surface veins may be more prominent
6. Leg fatigue:
o A feeling of heaviness in the affected limb
7. Homan's sign:
o Pain in the calf when the foot is dorsiflexed (not always reliable)

Note: It's important to recognize that up to 50% of DVT cases can be asymptomatic.

Diagnosis of DVT:

1. Clinical assessment:
o Patient history and physical examination
o Use of clinical prediction rules (e.g., Wells score)
2. D-dimer blood test:
o Measures a substance released when a blood clot breaks down
o High sensitivity but low specificity
o Useful for ruling out DVT when negative
3. Imaging studies: a) Compression ultrasound:
o First-line imaging test for suspected DVT
o Non-invasive and highly accurate

b) Duplex ultrasound:

o Combines compression ultrasound with Doppler flow studies

c) Venography:

o Contrast dye injected into veins and X-rays taken

o Considered the gold standard but invasive and rarely used now

d) CT venography:

o Uses CT scanning with contrast dye

o Useful for pelvic and abdominal veins

e) MR venography:
 o Uses magnetic resonance imaging
o Helpful for suspected pelvic vein thrombosis
4. Other laboratory tests:
o Complete blood count
o Coagulation profile (PT, aPTT)
o Thrombophilia screening in selected cases
5. Plethysmography:
o Measures changes in blood volume in the limb
o Less commonly used now
6. Impedance plethysmography:
o Detects changes in electrical conductivity of the leg
o Rarely used with the advent of ultrasound
7. Venous occlusion plethysmography:
o Assesses venous outflow obstruction
o Limited use in current practice
8. Thermography:
o Detects temperature differences
o Not widely used due to low specificity

MANAGEMENT

Medical Management:

1. Anticoagulation Therapy: a) Initial treatment:

o Low Molecular Weight Heparin (LMWH) (e.g., enoxaparin, dalteparin)
o Unfractionated Heparin (UFH) for patients with renal impairment
o Fondaparinux in some cases

b) Long-term treatment:

o Vitamin K antagonists (e.g., warfarin)

o Direct Oral Anticoagulants (DOACs):
▪ Factor Xa inhibitors (rivaroxaban, apixaban, edoxaban)
▪ Direct thrombin inhibitors (dabigatran)

c) Duration:

o Minimum 3 months, extended based on risk factors

2. Thrombolytic Therapy:
o Reserved for massive iliofemoral DVT or phlegmasia cerulea dolens
o Agents: tissue plasminogen activator (tPA), urokinase, streptokinase
3. Inferior Vena Cava (IVC) Filters:
o Used when anticoagulation is contraindicated or has failed
o Can be permanent or retrievable
4. Compression Therapy:
o Graduated compression stockings
o Intermittent pneumatic compression devices
5. Pain Management:
o NSAIDs or acetaminophen for mild pain
o Opioids for severe pain if necessary
 6. Management of Underlying Conditions:
o Treatment of cancer, if present
o Management of thrombophilia disorders

II. Surgical Management:

1. Catheter-Directed Thrombolysis:
o Localized delivery of thrombolytic agents
o Often combined with mechanical thrombectomy
2. Mechanical Thrombectomy:
o Removal of thrombus using specialized catheters
o Methods include aspiration, fragmentation, and rheolytic thrombectomy
3. Surgical Thrombectomy:
o Open surgical removal of thrombus
o Rarely used, reserved for severe cases
4. Venous Bypass:
o Creation of a bypass around the occluded segment
o Used in chronic cases with persistent symptoms
5. Angioplasty and Stenting:
o To treat residual stenosis after thrombus removal
o Often used in May-Thurner syndrome

III. Nursing Management:

1. Assessment and Monitoring:

o Regular evaluation of affected limb (swelling, pain, color, temperature)
o Monitoring for signs of bleeding (anticoagulation side effect)
o Assessing for signs of pulmonary embolism
2. Medication Administration and Monitoring:
o Administering anticoagulants as prescribed
o Educating patients on self-administration of injectable anticoagulants
o Monitoring coagulation parameters (e.g., INR for warfarin)
3. Patient Education:
o Explaining the disease process and treatment plan
o Teaching signs and symptoms of complications
o Instructing on proper use of compression stockings
o Educating about anticoagulant therapy and potential interactions
4. Mobility and Positioning:
o Encouraging early mobilization as appropriate
o Proper positioning to promote venous return (e.g., leg elevation)
5. Pain Management:
o Administering prescribed pain medications
o Non-pharmacological pain management techniques
6. Compression Therapy Management:
o Assisting with application of compression stockings
o Ensuring proper fit and use of compression devices
7. Wound Care:
o For patients with venous ulcers or post-procedure wounds
8. Psychosocial Support:
o Addressing anxiety related to diagnosis and treatment
 o Providing resources for long-term management
9. Discharge Planning:
o Arranging follow-up appointments
o Ensuring patient has necessary medications and equipment
o Providing contact information for emergencies
10. Prevention of Recurrence:
o Education on lifestyle modifications (e.g., avoiding prolonged immobility)
o Encouraging adherence to long-term treatment plans
11. Nutritional Counseling:
o Advising on diet, especially for patients on warfarin
12. Documentation:
o Maintaining accurate records of assessments, interventions, and patient
education