A nurse is evaluating a client who has heart failure and is receiving warfarin. Which of the following statements by the client indicates a need for further teaching?

Warfarin is an anticoagulant that prevents blood clots from forming or growing larger. It works by inhibiting the synthesis of vitamin K-dependent clotting factors in the liver. The INR (international normalized ratio) is a measure of how long it takes the blood to clot.The therapeutic range for INR depends on the indication for warfarin therapy, but for atrial fibrillation, it is usually between 2 and 3. An INR level of 3.5 is above the therapeutic range, which means the blood is too thin and the patient is at risk of bleeding. The nurse should hold the warfarin dose and notify the physician, who may order vitamin K to reverse the effects of warfarin.

Choice A) Administer vitamin K as ordered by physician is wrong because vitamin K is not indicated unless the physician orders it based on the patient’s condition and INR level.

Vitamin K is an antidote for warfarin overdose and can reverse its anticoagulant effects.

However, administering vitamin K without a physician’s order may cause the INR to drop below the therapeutic range and increase the risk of clotting.

Choice B) Administer heparin as ordered by physician is wrong because heparin is another anticoagulant that works by activating antithrombin, a natural inhibitor of clotting factors.

Heparin is used for acute treatment of thromboembolic disorders, such as deep vein thrombosis or pulmonary embolism.

It is not indicated for atrial fibrillation unless there is evidence of acute thrombosis.

Administering heparin to a patient with an elevated INR would increase the risk of bleeding.

Choice C) Administer warfarin as ordered by physician is wrong because warfarin is the cause of the elevated INR and should be withheld until the INR returns to the therapeutic range.

Continuing to administer warfarin would further increase the INR and the risk of bleeding.

Diuretics are drugs that increase the excretion of water and sodium by the kidneys, reducing blood volume and blood pressure.Diuretics lower blood pressure by dilating peripheral arterioles and decreasing blood volume by increasing the excretion of sodium and water.

Choice A is wrong because angiotensin-converting enzyme (ACE) inhibitors do not increase the excretion of water and sodium by the kidneys.ACE inhibitors block the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor and stimulator of aldosterone secretion.By reducing angiotensin II levels, ACE inhibitors lower blood pressure by dilating blood vessels and decreasing sodium and water retention.

Choice C is wrong because adrenergic drugs do not increase the excretion of water and sodium by the kidneys. Adrenergic drugs act on the sympathetic nervous system, which regulates heart rate, blood pressure, and other functions. Depending on the type and location of adrenergic receptors, adrenergic drugs can have different effects on blood pressure. Some adrenergic drugs can increase blood pressure by stimulating alpha receptors, which cause vasoconstriction.Other adrenergic drugs can decrease blood pressure by stimulating beta receptors, which cause vasodilation and decreased cardiac output.

Choice D is wrong because direct acting vasodilators do not increase the excretion of water and sodium by the kidneys. Direct acting vasodilators are drugs that relax the smooth muscle of blood vessels, causing them to widen and lower blood pressure.Direct acting vasodilators do not affect the renin-angiotensin-aldosterone system or the sympathetic nervous system, which regulate sodium and water balance.