Chapter 16.4: Deep Venous Thrombosis

Select the patient that would NOT be at risk of getting DVT.

You have a male post-knee arthroplasty patient that you are about to release back home. His wife is going to be the primary caregiver, so you are performing education on what the signs of DVT are. Which of the following statements made by the wife shows that she understands the teaching you have given?

Match the diagnostic test with its correct description: [blank_start]Duplex venous ultrasonography[blank_end]: Used to visualize vein and measure velocity of blood flow in the veins. Although the clot cannot be visualized, its presence can be inferred by an inability to compress the vein during examination. [blank_start]Ascending contrast venography[blank_end]: Most accurate diagnostic tool for venous thrombosis. A contrast medium is injected to assess the location and extent of venous thrombosis. [blank_start]Plethysmography:[blank_end] A noninvesive test that measures changes in blood flow through the veins. It is often used with Doppler ultrasonography. It is particularly useful in diagnosing thromboses of larger or superficial veins. [blank_start]Magnetic resonance imaging[blank_end]: A noninvesive test that is particularly useful in a thrombosis of the venae cavae or pelvic veins is suspected.

Heparin is an anticoagulant that interferes with the clotting cascade by inhibiting thrombin and preventing the conversion of fibrinogen to fibrin. If used at therapeutic levels, it prolongs thrombin time, clotting time, and aPTT. If given IV, it works immediately; if given SQ, it takes under an hour to work. It should be given frequently or continually because it has a short biological half-life. Select the nursing considerations for this drug (7 of these are right).

Which of the following is NOT proper patient and family teaching for this female patient on heparin?

Low molecular weight heparins provide a more precise and predictable anticoagulant effect than unfractionated heparins. They prevent the conversion of prothrombin to thrombin, liberation of thromboplastin from platelets, and formation of a stable clot. Which of the following is INCORRECT about low molecular weight heparins?

Select the PROPER patient teaching to give to a patient on a low-molecular weight heparin.

Warfarin interferes with the synthesis of vitamin-K dependent clotting factors by the liver. It has no effect on already circulating clotting factors or on existing clots. It does, however, inhibit the extension of existing thrombi and the formation of new clots. Its action is cumulative & more prolonged than heparin. Select the nursing considerations for this drug.

Which of the following is inappropriate teaching to give to a patient on warfarin?

Frequent monitoring of the infusion pump during anticoagulation therapy is an important nursing responsibility.

Anticoagulation is initiated with unfractionated or LMW heparin. The initial IV bolus should consist of [blank_start]7,500-10,000 units[blank_end] of unfractionated heparin, then the continuous heparin infusion should be at [blank_start]1,000-1,500 IU[blank_end] per hour (IU standing for "international units"). The dosage is calculated to maintain the [blank_start]aPTT[blank_end] at approximately [blank_start]twice[blank_end] the normal value. An infusion pump is used to deliver the prescribed dosage. LMW heparins are increasingly used to prevent and treat venous thrombosis. They do not require the close lab monitoring of unfractionated heparins. These heparins are administered [blank_start]subcutaneously[blank_end] in fixed doses, QD or BID, which allows outpatient treatment. These types of heparins are also more effective and carry lower risks for [blank_start]bleeding and thrombocytopenia[blank_end]. Warfarin may be initiated with heparin therapy. Overlapping therapy for [blank_start]4-5 days[blank_end] is important because the full anticoagulant effect of warfarin is delayed, and warfarin may actually promote clotting during the first few days of therapy. Warfarin doses are adjusted to maintain the INR at [blank_start]2.0-3.0[blank_end]. Once the INR has been achieved, [blank_start]heparin[blank_end] is discontinued and a maintenance dose of [blank_start]warfarin[blank_end] is prescribed. Anticoagulation will generally be continued for at least [blank_start]3 months[blank_end]. When DVT recurs or risk factors are present, anticoagulant therapy may be prolonged. Regular follow ups are necessary to be sure INR remains within the desirable range.

You have a 61-year-old patient that is presenting with a thrombosis in her deep femoral vein. She has already been placed on a LMW heparin. She is concerned that the DVT will not go away, and she is incredibly uncomfortable. What else can be done to help this patient? (3 of these are right).

You have a 71-year-old male post-knee replacement surgery. He has a history of hemphilia type B, so doctors deemed it unsafe to give him anticoagulants. Despite the usage of elastic antiembolism stockings and the history of hemophilia, the patient still develops a thrombus in his left popliteal vein. The patient can ambulate, but only very briefly and not for very long distances. He last reported his pain to be a 6/10. What are appropriate interventions for this patient?