A nurse is completing a medical interview with a client who has elevated cholesterol levels and takes warfarin. The nurse should recognize that which of the following actions by the client can potentiate the effects of warfarin?

Choice A reason: Warfarin PO is not a suitable medication for DVT prophylaxis in the immediate postoperative period, as it has a slow onset of action and requires frequent monitoring of the INR (international normalized ratio). Warfarin may be used for long-term anticoagulation, but it is not effective for preventing the formation of new clots.

Choice B reason: Enoxaparin subcutaneous is a suitable medication for DVT prophylaxis in the immediate postoperative period, as it has a rapid onset of action and does not require frequent monitoring of the coagulation status. Enoxaparin is a low-molecular-weight heparin that inhibits the formation of thrombin and prevents the growth of existing clots.

Choice C reason: Aspirin PO is not a suitable medication for DVT prophylaxis in the immediate postoperative period, as it has a weak anticoagulant effect and may increase the risk of bleeding. Aspirin is an antiplatelet agent that inhibits the aggregation of platelets and prevents the formation of arterial clots, but it is not effective for preventing venous clots.

Choice D reason: Heparin infusion is not a suitable medication for DVT prophylaxis in the immediate postoperative period, as it requires continuous intravenous administration and frequent monitoring of the aPTT (activated partial thromboplastin time). Heparin is an unfractionated heparin that inhibits the formation of thrombin and prevents the growth of existing clots, but it has a narrow therapeutic window and a high risk of bleeding.

Choice A reason: The nurse collects a urine specimen is an appropriate action, as it can help detect the presence of hemoglobinuria, which is a sign of hemolysis. Hemoglobinuria is the excretion of hemoglobin in the urine, which can cause the urine to appear red or brown.

Choice B reason: The nurse sends a blood specimen to the laboratory is an appropriate action, as it can help confirm the diagnosis of a hemolytic reaction and identify the cause. The laboratory can perform tests such as blood typing, cross-matching, direct antiglobulin test (DAT), and serum bilirubin.

Choice C reason: The nurse initiates an infusion of 0.9% sodium chloride is an appropriate action, as it can help maintain the client's fluid and electrolyte balance and prevent hypovolemic shock. 0.9% sodium chloride is the preferred solution for blood transfusion reactions, as it is isotonic and compatible with blood products.

Choice D reason: The nurse starts the transfusion of another unit of blood product is an inappropriate action, as it can worsen the client's condition and increase the risk of complications. The nurse should not resume the transfusion until the cause of the reaction is determined and the provider orders a new unit of blood product. The nurse should also return the unused blood product and tubing to the blood bank for analysis.