Prognosis of DVT

• Death occurs in approximately 6% of DVT cases – crucial to detect it early : within 1 month of diagnosis.
• Recurrence after the first event can be as high as 60% but halved by COMPRESSION STOCKINGS.
• With anticoagulant therapy, the mortality rate is decreased 5- to 10-fold.
• DVT recurs in 5% to 10% of patients the year after anticoagulant therapy is discontinued and in 30% of patients after 8 years.

• Most patients with proximal vein DVT are at long-term risk of chronic venous insufficiency. (30-80%)
• Approximately 20% of untreated proximal (above the calf) DVTs progress to pulmonary embolism.
• 10-20% of these PE cases are fatal.

• Post-phlebitic syndrome (chronic, potentially disabling condition) occurs in 15-50% of patients with deep vein thrombosis (DVT).
• Within a year or after the 1st attack.
• Recurrent attack increases the risk by 6 fold.
• It presents with

1. Leg oedema
2. Pain
3. Nocturnal cramping
4. Venous claudication
5. Skin pigmentation
6. Dermatitis
7. Ulceration (4-6% - usually on the medial aspect of the lower leg).

Differential Diagnosis

Superficial thrombophlebitis
Superficial vein thrombophlebitis is a common inflammatory-thrombotic process that may occur spontaneously or as a complication of medical or surgical interventions. Sterile thrombophlebitis limited to the superficial veins rarely is life threatening, but a thorough diagnostic evaluation is mandatory because many patients with superficial phlebitis also have occult deep vein thrombosis (DVT), which carries high rates of morbidity and mortality.
Patients with superficial thrombophlebitis often give a history of a gradual onset of localized tenderness, followed by the appearance of an area of erythema along the path of a superficial vein. A history of local trauma, prior similar episodes, varicose veins, prolonged travel, hormone use, tobacco use, family history of blood coagulopathies, or enforced stasis may be given. Asking about these risk factors for hypercoagulability should be done, but the absence of identifiable risk factors has no prognostic value.
• Traumatic thrombophlebitis: Ask about trauma, needlesticks, indwelling IV catheters, drug (eg, phenytoin) or hypertonic (10% calcium chloride) solution infusion and sclerotherapy.
• Thrombosed varicose veins: Ask about history of varicose veins


Varicose veins
Varicose veins and telangiectasia (spider veins) are the visible surface manifestations of an underlying problem with reverse venous flow, which is also termed venous insufficiency syndrome. Venous insufficiency syndromes describe venous blood deviating from a normal flow path and flow in a retrograde direction so that fluid accumulates, causing a "congested" leg.
Mild forms of venous insufficiency are merely uncomfortable, annoying, or cosmetically disfiguring, but severe venous disease can produce serious systemic consequences and can lead to loss of life or limb.
Most patients with venous insufficiency have subjective symptoms that may include pain, soreness, burning, aching, throbbing, cramping, muscle fatigue, and restless legs. Over time, chronic venous insufficiency leads to cutaneous and soft tissue breakdown that can be debilitating.


Cellulitis
The word cellulitis literally means inflammation of the cells. It generally indicates an acute spreading infection of the dermis and subcutaneous tissues resulting in pain, erythema, edema, and warmth.
Skin and subcutaneous tissues are involved when microorganisms, typically gram-positive bacteria, invade disrupted skin.

The skin disruption may be obvious, such as a laceration, fissure, or puncture wound. However, cellulitis frequently occurs in areas where no apparent injury exists. This is common in dry and irritated skin where microscopic breaks allow penetration of bacteria.

The infection triggers an inflammatory response that results in the clinically apparent pain, redness, warmth, and swelling.

Muscle Injury/Compartment Syndrome
Compartment syndrome (CS) is a condition in which the perfusion pressure falls below the tissue pressure in a closed anatomic space, with subsequent compromise of tissue circulation and function. Each muscle or muscle group is enclosed in a compartment bound by relatively rigid walls of bone and fascia. The compartments of the lower leg and the volar forearm are particularly prone to developing elevated compartment pressures.

As many as 45% of all cases of CS are caused by tibial fractures. Other causes include any long-bone fracture, vascular injury, compression in the setting of a crush injury, drug overdose, and a tight cast or dressing. Late manifestations of CS include the absence of a distal pulse, extremity paresis, and hypoesthesia. Compartment syndrome (CS) may be the result of either externally applied compressive forces or internally expanding forces. Fractures, vascular injuries, DVT, overexertion, fluid sequestration, or prolonged compression (as from a cast or other cause) may lead to CS. DVT rarely leads to CS, except in the most severe form of DVT, phlegmasia cerulea dolens.

Others:
Achilles tendonitis
Arterial insufficiency
Arthritis
Asymmetric peripheral edema secondary to CHF, liver disease, renal failure, or nephrotic syndrome
Cellulitis, lymphangitis
Extrinsic compression of iliac vein secondary to tumor, hematoma, or abscess
Hematoma
Lymphedema
Muscle or soft tissue injury
Neurogenic pain
Postphlebitic syndrome
Prolonged immobilization or limb paralysis
Ruptured Baker cyst
Stress fractures or other bony lesions
Superficial thrombophlebitis
Varicose veins

Signs and Symptoms of DVT

Signs and symptoms of deep vein thrombosis (DVT)
In about half of all cases, deep vein thrombosis occurs without any noticeable symptoms.
However, the classical symptoms of DVT include:
• Pain in your leg; this can include pain in your ankle and foot. This pain often starts in your calf and can feel like cramping or a "charley horse."
• Swelling in the affected leg, including swelling in your ankle and foot.
• Redness and warmth over the affected area.
• Pain or swelling in your arms or neck. This can occur if a blood clot forms in your arms or neck.
Not all of these symptoms have to occur; one, all, or none may be present with a deep vein thrombosis. The symptoms may mimic an infection or cellulitis (Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin) of the leg.
In up to 25% of all hospitalized patients, there may be some form of DVT, which often remains clinically unapparent (unless pulmonary embolism develops).
There are several techniques during physical examination to increase the detection of DVT, such as measuring the circumference of the affected and the contralateral limb at a fixed point (to objectivate edema), and palpating the venous tract, which is often tender. Physical examination is unreliable for excluding the diagnosis of deep vein thrombosis.
Historically, healthcare providers would try to elicit a couple of clinical findings to make a diagnosis. Dorsiflexion of the foot (pulling the toes towards the nose, or Homans' sign) and Pratt's sign (squeezing the calf to produce pain), have not been found effective in making a diagnosis.
It is vital that the possibility of pulmonary embolism be included in the history, as this may warrant further investigation (see pulmonary embolism).
If you develop signs or symptoms of a pulmonary embolism — a life-threatening complication of deep vein thrombosis — seek medical attention immediately.
The warning signs of a pulmonary embolism include:
 Unexplained sudden onset of shortness of breath
 Chest pain or discomfort that worsens when you take a deep breath or when you cough
 Feeling lightheaded or dizzy, or fainting
 Coughing up blood
 A sense of anxiety or nervousness

Etiology and Risk Factors of Deep Vein Thrombosis

What are the causes of deep vein thrombosis?

Blood is meant to flow; if it becomes stagnant there is a potential for it to clot. The blood in veins is constantly forming microscopic clots that are routinely broken down by the body. If the balance of clot formation and resolution is altered, significant clotting can occur. A thrombus can form if one, or a combination of the following situations is present.

Immobility - causes blood flow in the veins to be slow. Slow-flowing blood is more likely to clot than normal-flowing blood.

• Prolonged travel and sitting, such as long airplane flights ("economy class syndrome"), car, or train travel
• Hospitalization

• Surgery
• A surgical operation that lasts more than 30 minutes is the most common cause of a DVT. The legs become still when you are under anaesthetic. Blood flow in the leg veins can become very slow.

• Trauma to the lower leg with or without surgery or casting
• Pregnancy, including 6-8 weeks post partum
• About 1 in 1,000 pregnant women have a DVT while they are pregnant, or within about six months after they give birth.
• Obesity

Hypercoagulability (coagulation of blood faster than usual)

• Medications (for example, birth control pills, estrogen)
• The contraceptive pill and hormone replacement therapy (HRT) that contain oestrogen can cause the blood to clot slightly more easily.
• Smoking
• Genetic predisposition
• Polycythemia (increased number of red blood cells)
• Cancer
• Conditions that cause the blood to clot more easily than normal (thrombophilia)
• Some conditions can cause the blood to clot more easily than usual. For example, nephrotic syndrome and antiphospholipid syndrome. Some rare inherited conditions can also cause the blood to clot more easily than normal. For example, factor V Leiden

Trauma to the vein - Damage to the inside lining of the vein increases the risk of a blood clot forming. For example, a DVT may damage the lining of the vein. So, if you have a DVT, then you have an increased risk of having another one in the future. Some conditions such as vasculitis (inflammation of the vein wall) and some drugs (for example, some chemotherapy drugs) can damage the vein and increase the risk of having a DVT.

• Fracture to the leg
• Bruised leg
• Complication of an invasive procedure of the vein

Complication of Deep Vein Thrombosis (DVT)

Complication of Deep Vein Thrombosis (DVT)

Primary Complication

1.Pulmonary embolism

-Artery in the lungs is blocked by thrombus (usually from the legs)

-At least 10% of patients with DVT hv PE

-Can be fatal

-Sign and symptoms of pulmonary embolism include: unexplained dyspnea, angina (get worse when patient take a deep breath or cough), lightheaded/dizzy, and cough out blood

-Complication of PE includes: palpitation, heart failure, and pulmonary hypertension

2.Post-phlebitic syndrome

-Aka post-thrombotic condition

-2/3 patients will have this.

-A collection of signs and symptoms, including: edema, leg pain, hyperpigmentation, skin ulcer, varicose vein, PE

-Caused by damage to the veins, or a valve in the vein from the blood clot

-It reduces blood flow in the affected area

Other DVT Complications:

-less common

-renal vein thrombosis

-blood clot in the heart, leading to myocardial infarction

-stroke

References:

http://www.webmd.com/dvt/deep-vein-thrombosis-complications