I82.409

Acute embolism and thrombosis of unspecified deep veins of lower extremity

Acute embolism and thrombosis of unspecified deep veins of the lower extremity, commonly known as acute deep vein thrombosis (DVT), is a medical condition involving the formation of a blood clot within the deep venous system of the leg. This specific code is utilized when the clinical documentation confirms an acute DVT but lacks specificity regarding which vein (e.g., femoral, popliteal, tibial) or which side (right or left) is affected. The condition is primarily driven by Virchow's Triad: venous stasis, endothelial injury, and hypercoagulability. The chief clinical danger is the detachment of the thrombus (embolization), which can travel to the lungs and cause a potentially fatal pulmonary embolism (PE). Acute cases are those diagnosed in the early phase, where the clot is poorly attached to the vessel wall and carries the highest risk of migration. Management typically involves immediate anticoagulation therapy and evaluation for underlying risk factors.

Clinical Symptoms

Unilateral leg swelling
Pain or tenderness in the calf or thigh
Increased warmth in the affected extremity
Erythema or bluish skin discoloration
Pitting edema
Visible superficial vein distension
Leg heaviness or aching
Pain during dorsiflexion of the foot (Homan's sign)
Palpable venous cord in some instances
Low-grade fever

Common Causes

Prolonged immobilization or sedentary lifestyle
Major orthopedic surgery, particularly of the hip or knee
Recent abdominal or pelvic surgery
Active malignancy or history of cancer
Inherited thrombophilias such as Factor V Leiden or Protein C/S deficiency
Acquired hypercoagulable states such as Antiphospholipid Syndrome
Lower extremity trauma or fractures
Pregnancy and the immediate postpartum period
Oral contraceptive use or hormone replacement therapy
Advanced age
Obesity

Documentation & Coding Tips

Document specific laterality for all deep vein thrombosis cases to avoid unspecified codes like I82.409.

Example: Patient diagnosed with acute deep vein thrombosis. Review of outside hospital records confirms the presence of an acute clot in the lower extremity deep venous system. The specific side was not provided in the transfer summary, and the patient is currently in distress, precluding a detailed history. Plan: Immediate initiation of heparin protocol. Billing Focus: Laterality is missing in current documentation, necessitating I82.409. Risk Adjustment: This code maps to HCC 108, representing a significant acute vascular event.

Billing Focus: Laterality (Right, Left, or Bilateral)

Distinguish between acute and chronic deep vein thrombosis to ensure appropriate code selection.

Example: New onset of calf pain and swelling starting 24 hours ago. Venous duplex performed in the emergency department reveals a non-compressible segment in the deep venous system of the lower limb. This is an acute embolism and thrombosis event, not a chronic recurrence. Billing Focus: Acute versus chronic status. Risk Adjustment: Acute DVT represents a higher immediate severity and resource utilization than chronic DVT.

Billing Focus: Acuity (Acute vs. Chronic)

Specify the exact vein involved whenever possible to move beyond unspecified deep vein terminology.

Example: Clinical evaluation of the lower extremity indicates acute deep vein thrombosis. While the specific vein (e.g., femoral, popliteal, or tibial) is not yet identified by the bedside ultrasound, the deep system is involved. Billing Focus: Anatomical specificity. Risk Adjustment: Higher specificity allows for more accurate representation of the thrombotic burden.

Billing Focus: Anatomical site (e.g., Femoral, Popliteal, Tibial)

Document any associated complications such as pulmonary embolism or venous stasis syndrome.

Example: Patient admitted for acute deep vein thrombosis of the lower extremity. Also presenting with shortness of breath and tachycardia; CT pulmonary angiogram confirms associated acute pulmonary embolism. Billing Focus: Identification of secondary diagnosis codes (e.g., I26.99). Risk Adjustment: Presence of PE significantly increases the risk score and complexity.

Billing Focus: Comorbidities and complications

Clearly state the presence or absence of Provoked versus Unprovoked status in the clinical narrative.

Example: Acute deep vein thrombosis of the lower extremity following a 14-hour transcontinental flight. This is documented as a provoked DVT due to prolonged immobility. Billing Focus: Etiological factors. Risk Adjustment: Provoked status influences the duration of anticoagulation and long-term risk profile.

Billing Focus: Etiology (Provoked vs. Unprovoked)

Relevant CPT Codes

93970 - Duplex scan of extremity veins including responses to compression and other maneuvers; complete bilateral study
Primary diagnostic tool for identifying the location and extent of DVT.
93971 - Duplex scan of extremity veins including responses to compression and other maneuvers; unilateral or limited study
Used when symptoms are localized or for follow-up of a known thrombosis.
99214 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a moderate level of medical decision making
Standard level for managing an acute DVT requiring anticoagulation adjustment and monitoring.
99213 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a low level of medical decision making
Used for stable follow-up visits where the DVT is resolving and treatment is routine.
99204 - Office or other outpatient visit for the evaluation and management of a new patient, which requires a moderate level of medical decision making
Appropriate for the first visit where a DVT is diagnosed and a treatment plan is established.
37187 - Percutaneous transluminal mechanical thrombectomy, vein(s), including intraprocedural pharmacological thrombolytic injection and monitoring, initial vessel
Used in severe cases (e.g., phlegmasia cerulea dolens) or when anticoagulation is contraindicated.
37188 - Percutaneous transluminal mechanical thrombectomy, vein(s), including intraprocedural pharmacological thrombolytic injection and monitoring, subsequent vessel
Necessary when the thrombosis extends across multiple major venous segments.
85379 - D-dimer; quantitative
Used as a screening tool to rule out DVT in low-risk patients.
37191 - Insertion of intravascular vena cava filter, endovascular approach
Indicated for patients with acute DVT who cannot receive anticoagulants.
99215 - Office or other outpatient visit for the evaluation and management of an established patient, which requires a high level of medical decision making
Used for patients with DVT complicated by PE or major bleeding risks on anticoagulation.