A client who is receiving magnesium sulfate has a urine output of 20 mL/hr. Which of the following medications should the nurse expect to administer?

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: Applying a new transdermal patch when chest pain is experienced is not a correct instruction, as it may delay the relief of the pain and increase the risk of adverse effects. Transdermal nitroglycerin is a long-acting form of nitrate that is used for the prevention of angina attacks, not for the treatment of acute episodes. The client should use a short-acting form of nitrate, such as sublingual or spray, for the immediate relief of chest pain.

Choice B reason: Applying the transdermal patch in the morning is a correct instruction, as it helps to maintain a steady level of nitrate in the blood throughout the day and prevent angina attacks. Transdermal nitroglycerin has a duration of action of about 12 to 24 hours, depending on the dose and the individual response. The client should apply the patch in the morning and remove it at night, to allow a nitrate-free interval of at least 8 hours and prevent the development of tolerance.

Choice C reason: Applying the transdermal patch in the same location as the previous patch is not a correct instruction, as it may cause skin irritation and reduce the absorption of the medication. Transdermal nitroglycerin should be applied to a clean, dry, and hairless area of the skin, preferably on the chest, upper arm, or back. The client should rotate the application sites and avoid areas that are exposed to heat, moisture, or friction.

Choice D reason: Applying a new transdermal patch once a week is not a correct instruction, as it may not provide adequate protection against angina attacks and increase the risk of rebound angina. Transdermal nitroglycerin should be applied daily, with a nitrate-free interval of at least 8 hours, to maintain a therapeutic level of nitrate in the blood and prevent the loss of efficacy. The client should follow the prescribed dosing schedule and consult the provider before making any changes.