Final answer:
The most appropriate next step in managing the patient's superficial thrombophlebitis, secondary to varicose veins, is the initiation of anticoagulation therapy with Enoxaparin (choice B). Enoxaparin acts quickly and is the primary treatment to prevent thrombus extension. Supportive treatments are adjuncts but not the primary intervention.
Step-by-step explanation:
The patient described in the scenario appears to be suffering from lower limb superficial thrombophlebitis due to varicose veins, which are common in individuals who stand for prolonged periods, such as a supermarket cashier. Given the presence of a confirmed thrombus in the saphenous vein, the most appropriate next step in management is the use of anticoagulation therapy. The correct choice is B. Enoxaparin, which is a low-molecular-weight heparin used in the initial treatment of venous thromboembolism. Enoxaparin is preferred over warfarin for immediate anticoagulation due to its faster onset of action. Warfarin may be initiated concurrently and then continued after enoxaparin for a longer duration of therapy. Supportive measures like rest, elevation, and non-steroidal anti-inflammatory agents can also be used to manage symptoms, but the priority is to initiate anticoagulation. A spiral CT of the chest would be considered if there were signs of pulmonary embolism, and placement of an inferior vena cava filter is generally reserved for cases where anticoagulation is contraindicated or has failed.