Pharmacotherapy Case Study 11: Deep Vein Thrombosis (DVT) By: Dr. Nehad Ahmed

 

Chief Complaint:

A 45-year-old male presents to the clinic with complaints of swelling, pain, and redness in his left calf for the past 3 days. He reports a sensation of heaviness in his left leg, which has worsened over the last 24 hours. He has not noticed any signs of injury but has been relatively inactive due to a recent long flight.

Subjective Data:

History of Present Illness (HPI):
The patient reports noticing swelling and pain in his left calf over the past 3 days. He describes the pain as dull and aching, located primarily in the lower leg, with the swelling becoming more pronounced by the end of the day. The pain is worsened with standing and walking. The patient denies any history of trauma, but he recently completed a long international flight (approximately 10 hours) 5 days ago, which is when he first began experiencing discomfort. He has not had any fever or chills, and no history of chest pain, shortness of breath, or coughing.

Past Medical History (PMH):

Hypertension (diagnosed 8 years ago)

Obesity (BMI 31 kg/m²)

Hyperlipidemia (diagnosed 5 years ago)

Type 2 Diabetes Mellitus (diagnosed 4 years ago)

Previous history of DVT in the right leg, 4 years ago, treated with anticoagulation therapy.

No history of surgery, fractures, or immobilization other than the recent flight.

Medications:

Lisinopril 20 mg daily

Metformin 1000 mg twice daily

Atorvastatin 40 mg nightly

Aspirin 81 mg daily (for cardiovascular prophylaxis)

No current use of anticoagulation therapy.

Allergies:

No known drug allergies.

Family History:

Father had a history of myocardial infarction at age 55.

Mother has hypertension and hyperlipidemia.

Social History:

Smoking: Former smoker (1 pack/day for 15 years, quit 6 years ago).

Alcohol: Drinks 3-4 alcoholic beverages per week.

Occupation: Works as an office manager, desk job, mostly sedentary during work hours.

Physical activity: Inactive, does not engage in regular exercise.

Diet: High in processed foods and low in fruits and vegetables.

Review of Systems:

Cardiovascular: No chest pain, palpitations, or shortness of breath.

Respiratory: No cough, wheezing, or hemoptysis.

Gastrointestinal: No nausea, vomiting, or abdominal pain.

Neurological: No dizziness, weakness, or numbness.

Musculoskeletal: Pain and swelling in the left calf.

Objective Data:

Vital Signs upon Arrival:

Blood Pressure: 130/85 mmHg

Heart Rate: 78 bpm

Respiratory Rate: 16 breaths/min

Temperature: 36.9°C

Oxygen Saturation: 97% on room air

Weight: 110 kg (BMI 31 kg/m²)

Height: 175 cm

Physical Exam:

General: Patient appears alert and in mild discomfort due to calf pain. No signs of acute distress.

Cardiovascular:

Heart sounds normal (S1, S2).

No jugular venous distention (JVD).

No peripheral edema or signs of heart failure.

Respiratory: Clear breath sounds bilaterally. No signs of respiratory distress.

Abdomen: Soft, non-tender, no hepatomegaly or ascites.

Extremities:

Left lower leg notably swollen from mid-calf to ankle, with redness and warmth over the affected area.

Tenderness to palpation along the left calf.

Positive Homan’s sign: pain on dorsiflexion of the left foot.

No signs of deep vein thrombosis in the right leg.

Neurological:

Alert and oriented to time, place, and person.

No focal neurological deficits.

Laboratory Results:

Electrolytes: Sodium 140 mEq/L, Potassium 4.2 mEq/L, Chloride 101 mEq/L

Creatinine: 1.2 mg/dL (normal renal function)

Blood Glucose: 155 mg/dL (elevated, stress hyperglycemia)

Complete Blood Count (CBC): Normal white blood cell count, hemoglobin 14.0 g/dL, hematocrit 41%

D-dimer: 2.5 µg/mL (elevated, suggests possible clot formation)

Coagulation Profile:

INR: 1.0 (on aspirin therapy)

Lipid Profile:

Total Cholesterol: 215 mg/dL

LDL: 135 mg/dL

HDL: 38 mg/dL

Triglycerides: 190 mg/dL

Ultrasound:

Left lower extremity venous duplex ultrasound: Positive for a proximal deep vein thrombosis (DVT) in the left popliteal vein, confirming the clinical suspicion of DVT.

Chest X-ray:

Clear lung fields, no signs of pulmonary embolism (PE) or pneumonia.

Assessment:

The patient is diagnosed with deep vein thrombosis (DVT) in the left popliteal vein, which is likely caused by recent prolonged immobility during the long flight. He exhibits classic signs of DVT, including pain, swelling, and redness in the affected leg, with a positive Homan’s sign. The elevated D-dimer also supports the presence of clot formation, although it is not specific for DVT. The venous duplex ultrasound confirmed the diagnosis.

The patient has risk factors for DVT, including obesity, sedentary lifestyle, recent long flight, and a previous history of DVT. His hypertension, diabetes, and hyperlipidemia also contribute to his overall vascular risk. There is no evidence of pulmonary embolism (PE) at this time, as the patient denies shortness of breath, chest pain, or hemoptysis.

Plan:

Immediate Management:

Anticoagulation therapy: Initiate low molecular weight heparin (LMWH) (enoxaparin 1 mg/kg subcutaneously every 12 hours) or unfractionated heparin for inpatient management to prevent clot extension and embolization.

Transition to oral anticoagulation (e.g., apixaban or rivaroxaban) for long-term management once stabilized, or continue with warfarin with a target INR of 2-3.

Compression stockings: Recommend wearing graduated compression stockings for symptom relief and to reduce the risk of post-thrombotic syndrome.

Elevation of the affected leg: Instruct the patient to elevate the left leg whenever possible to reduce swelling.

Pain management: Administer acetaminophen or ibuprofen for pain relief.

Close monitoring: Monitor for signs of pulmonary embolism (PE), particularly if the patient develops sudden shortness of breath, chest pain, or hemoptysis. Consider a CT pulmonary angiogram if these symptoms arise.

Long-Term Management:

Oral anticoagulation: Initiate apixaban 5 mg twice daily or rivaroxaban 15 mg twice daily for 21 days, then reduce to 20 mg once daily, or transition to warfarin with an INR target of 2-3.

Duration of anticoagulation therapy:

If DVT was provoked by recent surgery, trauma, or long flight, treat with anticoagulation for at least 3 months.

For unprovoked DVT or recurrent DVT, longer-duration therapy may be indicated.

Regular follow-up: Monitor for any side effects or complications of anticoagulation, such as bleeding. Follow-up visits to assess the effectiveness of therapy and manage anticoagulation dosing.

Lifestyle Modifications:

Weight management: Advise the patient to follow a weight loss plan to reduce obesity and its associated risk for DVT recurrence.

Increase physical activity: Encourage regular ambulation, exercise, and periodic leg movement, especially during long periods of immobility (e.g., during travel).

Dietary modifications: Recommend a low-sodium, heart-healthy diet to support overall vascular health and reduce cardiovascular risk.

Education:

Educate the patient on the signs and symptoms of pulmonary embolism (PE), including sudden shortness of breath, chest pain, or coughing up blood, and instruct him to seek immediate medical attention if these occur.

Discuss the importance of medication adherence to prevent clot recurrence and avoid missing doses of anticoagulants.

Follow-up:

Follow-up in 1 week for assessment of symptoms and anticoagulation therapy effectiveness.

Regular follow-up with primary care physician for management of comorbidities such as hypertension, diabetes, and hyperlipidemia.

Discussion:

Deep vein thrombosis (DVT) is a common and serious condition that can lead to significant morbidity, including pulmonary embolism (PE) if not managed properly. In this case, the patient’s long flight and sedentary lifestyle likely contributed to the development of DVT. Anticoagulation therapy remains the cornerstone of DVT management to prevent clot extension and embolization.

The management of DVT involves initial parenteral anticoagulation (LMWH or heparin) followed by oral anticoagulation for a prolonged period. The patient’s previous history of DVT and current risk factors make long-term anticoagulation therapy necessary. Furthermore, lifestyle modifications such as weight loss and increased physical activity are critical in reducing the risk of future thromboembolic events.

Prognosis:
With appropriate treatment and lifestyle changes, the prognosis for this patient is generally good. Long-term anticoagulation therapy and lifestyle modifications will help reduce the risk of recurrent DVT and pulmonary embolism, but regular monitoring is necessary to ensure therapeutic anticoagulation and early detection of any complications.