September 26, 2011

Coding for Acute and Chronic DVT and PE
For The Record
Vol. 23 No. 17 P. 31

Deep venous thrombosis (DVT) is a condition where a blood clot develops in a deep vein. Typically located in the legs and thighs, DVT can be found anywhere in the body and occurs when the blood thickens and clumps together. Deep veins are found within groups of muscles and superficial veins are located close to the skin. If a blood clot develops in a deep vein, it may be serious because it can break loose and travel to the lungs—a condition called pulmonary embolism (PE). Blood clots that develop in superficial veins are not as risky because they cannot dislodge and travel to the lungs.

In cases of severe, life-threatening pulmonary embolism, definitive treatment consists of dissolving the clot with thrombolytic therapy (streptokinase, urokinase, or tissue plasminogen activator). Additionally, anticoagulant therapy is used to prevent the formation of more clots and allows the body to reabsorb the existing clots faster. Anticoagulation typically involves IV heparin, along with oral warfarin (Coumadin). Subcutaneous low-molecular weight heparin (Lovenox) may be substituted for intravenous heparin. An inferior vena cava filter may be placed in patients who cannot tolerate anticoagulation therapy or are at high risk of developing further clots due to underlying medical conditions. In rare cases and usually with larger emboli, surgery will sometimes be needed. Heparin will usually be administered until the patient’s international normalized ratio (INR) reaches therapeutic levels. Once therapeutic levels are reached, the patient is typically discharged on oral Coumadin or subcutaneous Lovenox. The patient will generally be continued on anticoagulants for at least six months after discharge, and INRs will routinely be monitored on an outpatient basis to maintain levels within a therapeutic range (often 2.0 – 3.0).

Acute vs. Chronic DVT
ICD-9-CM codes were created and existing code titles were revised in 2009 to help distinguish between acute and chronic DVT. Typically, an acute DVT is considered a new thrombosis that requires the initiation of anticoagulant therapy. A chronic DVT is an old or previously diagnosed thrombus that requires continuation of anticoagulation therapy. However, specific code assignment is based on physician documentation. The coder cannot assume whether the DVT is acute or chronic unless the physician documents the acuity. A patient with a history of DVT receiving Coumadin or requiring a Greenfield filter will require additional clarification before final code assignment can be determined. The Coumadin may be prescribed for prophylactic purposes to prevent recurrence or as treatment for chronic DVT. The Greenfield filter may be inserted for acute, chronic, recurrent DVT or the susceptibility for recurrence. The physician is responsible for providing the acuity of the condition. There are no specific guidelines for when DVT is considered chronic. The code assignment for chronic DVT is based solely on physician documentation. In addition, documentation of subacute DVT is classified to the code for acute DVT (AHA Coding Clinic for ICD-9-CM, 2011, first quarter, pages 20-21). History of DVT is classified to code V12.51, Personal history of venous thrombosis and embolism.

Acute vs. Chronic PE
Diagnosis of chronic pulmonary embolic disease usually occurs following discovery of pulmonary hypertension (usually via ECHO, ventilation/perfusion scan, or CT). Definitive confirmation is usually obtained via pulmonary angiogram. Medical treatment is initiated based on disease severity and symptomatology but generally includes anticoagulant therapy. For more symptomatic pulmonary hypertension secondary to chronic thromboembolic disease, patients may be placed on sildenafil (Viagra) for arterial dilation. For patients with more severe symptomatology, surgical removal may be considered. Unfortunately, the most symptomatic patients may not be able to tolerate surgical removal. For those determined to be good surgical candidates, a thromboendarterectomy may be performed if the embolism is proximal enough to access. For patients with more distal thrombus, a sternal approach is used and the artery directly dissected and the occlusion removed. The procedure is usually performed with the patient on cardiopulmonary bypass.

ICD-9-CM Code Assignment
Also documented as venous thrombosis and venous thromboembolism, DVT is classified to the following ICD-9-CM codes:

• 453.4, Acute venous embolism and thrombosis of deep vessels of lower extremity—the fifth-digit subclassification identifies the specific vessel in the lower extremity;

• 453.5, Chronic venous embolism and thrombosis of deep vessels of lower extremity—the fifth-digit subclassification identifies the specific vessel in the lower extremity;

• 453.6, Venous embolism and thrombosis of superficial vessels of lower extremity;

• 453.7, Chronic venous embolism and thrombosis of other specified vessels—the fifth-digit subclassification identifies chronic thrombosis of the superficial and deep vessels of the upper extremity, axillary veins, subclavian veins, internal jugular veins, other thoracic veins, and other specified veins;

• 453.8, Acute venous embolism and thrombosis of other specified veins—the fifth-digit subclassification identifies acute thrombosis of the superficial and deep vessels of the upper extremity, axillary veins, subclavian veins, internal jugular veins, other thoracic veins, and other specified veins;

• 453.0, Hepatic vein thrombosis;

• 453.2, Venous thrombosis of vena cava; and

• 453.3, Venous thrombosis of renal vein.

If the DVT is documented as a postoperative complication or iatrogenic, then code 997.2, Peripheral vascular complication, not elsewhere classified, is sequenced first followed by the code for the specific site of the DVT.

If the patient is diagnosed with both DVT and thrombophlebitis, it is appropriate to assign a code for both conditions. The diagnoses are two separate conditions and can occur together or separately. This advice supersedes advice from Coding Clinic, third quarter 1991 and first quarter 1992 (AHA Coding Clinic for ICD-9-CM, 2011, first quarter, page 19).

If PE is also present with DVT, then one of the following codes may also be assigned with the code for DVT:

• 415.11, Iatrogenic pulmonary embolism and infarction;

• 415.12, Septic pulmonary embolism (code first the underlying infection);

• 415.19, Other pulmonary embolism and infarction; or

• 416.2, Chronic pulmonary embolism.

Sequencing of DVT and PE will depend on the circumstances of admission.

Coding and sequencing for acute and chronic DVT and PE are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.

— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to more than 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com or by calling 800-367-2447.

 

Coding for DVT in ICD-10
A patient admitted with a deep venous thrombosis (DVT) of the lower extremity will need to have more specific documentation in ICD-10, to indicate the specific vein, such as femoral or iliac, along with laterality to indicate the actual side of the body involved. If the DVT is of the left femoral vein, it is reported as I82.412.

Treatment of choice is a vena cava or Greenfield filter. The objective of this procedure is to filter clots from the blood and not to restrict blood flow. The root operation to use is insertion, or “putting in a nonbiological appliance that monitors, assists, performs, or prevents a physiologic function but does not physically take the place of a body part.” The filter is usually placed percutaneously in the inferior vena cava. The inferior vena cava is part of the “lower veins” body system with the body part specifically identified as the inferior vena cava. The ICD-10-PCS code used to identify a percutaneous insertion of a vena cava filter is 06H03DZ, with the following description of each character:

• 0, Medical and surgical

• 6, Lower veins

• H, Insertion

• 0, Inferior vena cava

• 3, Percutaneous

• D, Intraluminal device

• Z, No qualifier

— This information was prepared by Donna M. Smith, RHIA, senior consultant at 3M Health Information Systems.