From the Guidelines
When a patient presents to the emergency room with calf pain, the initial approach should focus on ruling out serious conditions like deep vein thrombosis (DVT) while identifying the underlying cause. Begin with a thorough history and physical examination, noting risk factors for DVT such as recent immobility, surgery, or hormonal therapy. Assess the character of pain, onset, radiation, and associated symptoms like swelling or redness. Physical examination should include inspection for swelling, warmth, tenderness, and palpation of distal pulses. The Wells criteria can help stratify DVT risk, with scores guiding further management. For patients with moderate to high DVT risk, order a D-dimer test and consider ultrasound imaging, as recommended by the American Society of Hematology 2018 guidelines for management of venous thromboembolism: diagnosis of venous thromboembolism 1. If DVT is confirmed, initiate anticoagulation therapy with either low molecular weight heparin (enoxaparin 1mg/kg twice daily) or direct oral anticoagulants like rivaroxaban (15mg twice daily for 21 days, then 20mg daily). For musculoskeletal causes of calf pain, recommend rest, ice, compression, elevation (RICE), and NSAIDs like ibuprofen 400-600mg three times daily with food. Other potential causes requiring specific workup include compartment syndrome (measure compartment pressures if suspected), ruptured Baker's cyst (ultrasound imaging), or arterial insufficiency (ankle-brachial index), as outlined in the 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS guideline for the management of lower extremity peripheral artery disease 1. Provide clear discharge instructions including warning signs that should prompt return to the emergency department, such as increasing pain, numbness, or color changes in the affected limb. It is also important to consider the patient's overall clinical presentation and medical history, as well as the results of diagnostic tests, when determining the best course of treatment, as noted in the cancer-associated venous thromboembolic disease, version 2.2024, NCCN clinical practice guidelines in oncology 1. Additionally, the use of complete ultrasound protocols, as recommended by the Society of Radiologists in Ultrasound Consensus Conference, can help to identify DVT and other potential causes of calf pain 1. Ultimately, the goal of treatment is to reduce morbidity, mortality, and improve quality of life, and the approach should be tailored to the individual patient's needs and circumstances.
From the Research
Calf Pain Approach in Emergency Room
- The approach to calf pain in the emergency room involves a multifaceted diagnosis that includes clinical assessment, evaluation of pre-test probability, and objective diagnostic testing 2.
- Common symptoms and signs of deep vein thrombosis (DVT) are pain, swelling, erythema, and dilated veins in the affected limb 2.
- The pre-test probability of DVT can be assessed using a clinical decision rule that stratifies DVT into "unlikely" or "likely" 2.
- If DVT is "unlikely", a D-dimer test can be used to exclude DVT, while if the D-dimer level is increased, compression ultrasound can be used for further diagnosis 2.
Diagnostic Tests
- D-dimer testing has a high negative predictive value, but small thrombi may be associated with low D-dimer levels, increasing false negatives 3.
- The false negative rate of the standard D-dimer cut-off was 2% for proximal DVT and 14.7% for isolated distal DVT (IDDVT) 3.
- Complete compression ultrasonography is a useful diagnostic tool for DVT, especially in patients with suspected IDDVT 3.
- Other imaging modalities such as CT, MRI, or nuclear medicine tests can be considered in select scenarios 4.
Management
- Anticoagulation is indicated to control symptoms, prevent progression, and reduce the risk of post-thrombotic syndrome and pulmonary embolism in patients with confirmed DVT 2.
- Direct oral anticoagulants (DOACs) are the preferred treatment for DVT because they are at least as effective, safer, and more convenient than warfarin 2.
- DOACs may require dose reduction or avoidance in patients with renal dysfunction and should be avoided in pregnancy 2.