Thrombotic Disorders

Answer: D

Explanation: Patients receiving thrombolyisis must be monitored very closely. Oozing from line sites and elevation of D-dimers indicate that thrombolysis is occurring and the bleeding can be managed with local pressure. Reduced fibrinogen and platelet counts are expected and can be replaced easily. A drop of hemoglobin > 2 g/dl in a 24-hour period indicates excessive/major bleeding, so thrombolysis should be discontinued to assess and correct the bleeding.

Question 14

Answer: B

Explanation: Screening children for thrombophilia is heavily debated. However, it is unnecessary to test this child for every thrombophilic abnormality (particularly the acquired ones like antiphospholipid antibodies). Testing only for FV Leiden is not the best approach, either. FV Leiden is the most common inherited mutation (up to 5% of Caucasian population), but the prothrombin gene mutation occurs in 2%–3%. The maternal side of the family also may have either of these mutations and it is well recognized that multiple thrombophilic defects increases a person’s risk more than a single mutation. In addition, a negative FV Leiden screen would not necessarily mean that this child is protected from thrombosis. In a healthy child, there is no reason to initiate prophylactic anticoagulation. Therefore, the best approach is to teach the family signs and symptoms of thrombosis and under which situations the child would be at highest risk. During high-risk situations, the child may benefit from some simple, noninvasive preventive measures such as use of compression stockings, adequate hydration, and early ambulation.
Question 15

Answer: A

Explanation: Family history of a provoked DVT is not an indication for chronic anticoagulation therapy. Indications would be persistently elevated FVIII activity, strong thrombophilia (protein C, S, or antithrombin deficiency), and antiphospholipid antibody (APLA) syndrome. Although the protein C activity is technically low for an adult, it is normal for a preteen. Normal adult levels are not achieved until adolescence. If there is a concern for inherited protein C deficiency, antigen testing as well as activity testing should be repeated in a couple of years. Heterozygous FV Leiden is a mild thrombophilia and will not require indefinite anticoagulation because risk of recurrence is not higher for these patients; however, they will need DVT prophylaxis in high-risk situations. Antiphospholipid antibody syndrome is defined as the persistence of APLAs or lupus anticoagulant for 12 weeks in context of thrombotic event. This is associated with high risk of recurrent events.