A 60-year-old woman with DVT after flight, on heparin. Next diagnostic tests?

Correct Answer: D

Rationale: The correct answer is D: No further testing. In this scenario, the patient has a clear risk factor for DVT (long flight) and is already on anticoagulation therapy. Further diagnostic tests are not necessary for the management of acute DVT in this case. Testing for Factor V Leiden or Protein C, S, antithrombin III levels would not change the management at this point. Antiphospholipid antibody test is not indicated as there are no signs or symptoms suggestive of antiphospholipid syndrome. The most appropriate action is to continue the current treatment and monitor the patient's response.

Correct Answer: A

Rationale: The correct answer is A because the absence of palpable radial/pedal pulses indicates poor perfusion, a critical concern in DIC. This finding suggests compromised blood flow, requiring urgent intervention to prevent tissue damage. Choices B, C, and D are not immediate concerns in DIC. Chest pain may indicate cardiac issues, but perfusion is the priority. Oxygen saturation at 87% is low but not as urgent as impaired perfusion. Mottling of hands and feet is a sign of poor perfusion but not as immediate as the absence of palpable pulses.

Correct Answer: A

Rationale: The correct answer is A: Serum potassium 7.8 mEq/L. A high serum potassium level (hyperkalemia) can lead to life-threatening cardiac arrhythmias. Rapid action is necessary to prevent cardiac complications. Urine output slightly less than intake (choice B), oral mucosa inflammation (choice C), and ecchymoses on trunk (choice D) are important but do not require immediate action to prevent fatal consequences like hyperkalemia.

Correct Answer: C

Rationale: Correct Answer: C (Tissue factor) Rationale: 1. Tissue factor initiates the extrinsic pathway of the coagulation cascade by forming a complex with Factor VII. 2. This complex activates Factor X to Xa, leading to the common pathway of coagulation. 3. Factor XII is part of the intrinsic pathway and is not the primary initiator in vivo. 4. Thrombin is generated downstream in the cascade and amplifies coagulation but does not initiate it. 5. Factor X is activated further downstream in the common pathway and is not the primary initiator.

Correct Answer: C

Rationale: The correct answer is C: Diffuse large B-cell lymphoma. This is the most common type of lymphoma due to its aggressive nature and frequent occurrence in adults. It accounts for about 30% of all non-Hodgkin lymphomas. Hodgkin lymphoma (A) is less common and has distinct diagnostic features. Follicular lymphoma (B) is indolent and typically affects older adults. Mantle-cell lymphoma (D) is rarer and characterized by a specific genetic abnormality. Therefore, based on prevalence and characteristics, diffuse large B-cell lymphoma is the most common type.