Deep Vein Thrombosis (DVT) – Diagnosis, Documentation and Coding

March is national Deep-Vein Thrombosis (DVT) Awareness Month. This public health initiative aims to raise awareness about this widely prevalent medical condition and its potentially life-threatening complication, pulmonary embolism (PE). The American Medical Association estimates that about 2 million people are affected by DVT each year, more than the numbers affected by heart attack or stroke annually. Billing and coding for these conditions is complex. An experienced medical billing and coding service provider would have proper knowledge of important diagnostic norms and documentation requirements to help physicians assign appropriate diagnoses and procedure codes on claims.

What is DVT?

DVT occurs when a blood clot (thrombus) forms in one or more veins located deep inside the body. This serious condition occurs when the blood moves too slowly through the veins due to long periods of immobility or reduced mobility or other factors. DVT typically occurs in the lower leg, thigh, or pelvis, but can also occur in other parts of the body. If the blood clot breaks off and travels through the bloodstream, it can block a blood vessel of the lung. This causes the fatal condition known as a pulmonary embolism.

DVT Symptoms and Risk Factors

Symptoms of DVT can include

• Swelling in the foot, ankle, or leg
• Cramping and pain
• swollen veins
• Tenderness
• Discoloration
• Unusually hot skin in the affected area

If DVT occurs with no identifiable risk factor, the condition is called unprovoked DVT.

There are many risk factors for DVT. The most common risk factors include prior DVT, obesity, smoking, stroke, pregnancy, hormone therapy, varicose veins, being over the age of 65, and prolonged immobility because of bed rest or travel.

Diagnosis

The problem with diagnosing DVT is that in most cases, symptoms are minimal and sometimes absent. The presence of certain conditions such as muscle strain, skin inflection, and inflammation of veins (phlebitis) can also make DVT difficult to diagnose.

Methods use to diagnose DVT or check for a blood clot include:

• Venous Ultrasound: This standard test for DVT involves using sound waves to display how blood flows through the veins.
• Venography: This x-ray test involves injecting a dye into a large vein in the foot or ankle to detect clots.
• D-Dimer Blood Test: People with severe DVT have high levels of D dimer in the blood.
• Impedance Plethysmography: Also known as compression ultrasonography, this highly sensitive test detects DVT using electrodes and a blood pressure cuff placed on the calf and thigh. The recently released guidelines of the European Society for Vascular Surgery (ESVS) recommend using ultrasonography as the first modality in a setting of suspected DVT.
• Magnetic Resonance Imaging (MRI): An MRI scan may be used to diagnose DVT in veins of the abdomen.

Treatment

The aim of DVT treatment is to stop the blood clot from increasing in size or breaking off and moving toward the lungs as well as reducing the patient’s risks of another episode. Therapies include:

• Anticoagulant Medications: Usually, heparin is prescribed first to prevent further clotting, which may be followed by warfarin to prevent another blood clot forming.
• Inferior Vena Cava (IVC) Filter: This small, cone-shaped filter is inserted into the inferior vena cava, the largest vein in your body. The filter can prevent a large clot from reaching the lungs.
• Compression Stockings: These special stocking fit in a way to prevent blood from pooling in the veins and ease symptoms.

Documenting and Coding DVT

Correct ICD-10 coding for DVT requires documentation to the highest level of specificity. Key points to note for proper coding:

• Distinguishing Between DVT and Venous Thrombosis with Phlebitis: The term “DVT” indicates venous thrombosis without accompanying phlebitis or inflammation of a vein. “Thrombophlebitis” is the term for venous thrombosis with phlebitis. Thrombophlebitis is due to one or more blood clots in a vein that cause inflammation. DVT, deep vein thrombophlebitis, or central vein thrombosis are the the most common causes of PE.
• Documenting to the Highest Level of Specificity: Providers should clearly document whether DVT is acute, chronic or historical. A diagnosis of acute thrombosis is assigned when a new, symptomatic thrombosis is detected and anticoagulation therapy is being started; chronic is assigned when the condition is established, and the patient needs lifelong anticoagulation therapy; the condition is historical when patient no longer has thrombosis but is on anticoagulant therapy as a preventive measure.
• Specifying Laterality, Location, and Vein: The documentation should indicate:
  • Laterality – side of the body, i.e., left or right
  • The specific location – upper or lower extremity
  • The specific vein such as femoral, iliac or tibial

The physician should also document the diagnostic method used, the anticoagulants administered and duration of treatment. The treatment and its goals should be linked to the diagnosis.

ICD 10 Codes for DVT of Lower Extremities and Upper Extremities – Acute and Chronic

Acute embolism and thrombosis of lower extremity

I82.41 femoral vein
182.42 Iliac vein
I82.43 Popliteal vein
I82.44 Tibial vein
I82.45 Peroneal vein
I82.46 Calf muscular vein
I82.49 Other specified deep vein of lower extremity

Chronic embolism and thrombosis of lower extremity

182.52 Iliac vein
I82.53 Popliteal vein
I82.54 Tibial vein
I82.55 Peroneal vein
I82.56 Calf muscular vein
I82.59 Other specified deep vein of lower extremity

Acute embolism and thrombosis of upper extremity

I82.61 Superficial veins of upper extremity
I82.62 deep veins of upper extremity
I82.A1 Axillary vein
I82.B1 Subclavian vein
I82.C1 Internal jugular vein

Chronic embolism and thrombosis of upper extremity

I82.71 Superficial veins of upper extremity
I82.72 Deep veins of upper extremity
182.A2 Axillary vein
I82.B2 Subclavian vein
I82.C2 Internal jugular vein

The personal history codes for “history of” DVT, thrombophlebitis, and PE are Z86.718, Z86.72, and Z86.711, respectively.

As a secondary diagnosis, all codes for acute and chronic DVT are categorized as complications/comorbidities (CCs) and almost all of them are included in HCC 108, vascular disease without complication (ACP Hospitalist).

Combating DVT

As the nation observes DVT Awareness Month, leading medical, public health and patient advocacy groups are working towards educating the public about the signs, symptoms and risk factors of this serious medical condition. Though DVT can develop without any obvious reason and is not entirely preventable, taking appropriate preventative measures can reduce the risk of formation of a blood clot. Preventive measures to maintain good circulation include:

• Living an active life with regular exercise
• Maintaining a healthy weight
• Avoiding long periods of inactivity or immobility
• Moving legs when on a long flight
• Wearing compression stockings if at risk for DVT

Health professionals should focus on early diagnosis and treatment of DVT to minimize the risk of complications. Ensuring clear and comprehensive documentation is crucial for medical coding service providers to use the right codes to represent the diagnosis accurately.