A nurse is teaching the partner of a client who had an acute myocardial infarction (MI) about the reason blood was drawn from the client. Which of the following statements should the nurse make regarding cardiac enzyme studies?

Nitroglycerin is a vasodilator that relaxes smooth muscle in blood vessels and reduces myocardial oxygen demand. It is used to treat and prevent angina atacks. A common side effect of nitroglycerin is headache, which is caused by cerebral vasodilation. The nurse should advise the client to take a mild analgesic, such as acetaminophen, to relieve the headache. The headache usually subsides with continued use of nitroglycerin.

The other options are not correct because:

"Take only one dose of nitroglycerin to reduce the risk of getting a headache." This statement is incorrect because it may compromise the effectiveness of nitroglycerin in relieving angina. The client should follow the prescribed dosage and frequency of nitroglycerin, which is usually one tablet every 5 minutes for up to three doses, as needed for chest pain.

"There's nothing that can be done to relieve the headaches that nitroglycerin causes." This statement is incorrect because it is discouraging and dismissive of the client's concern. The nurse should acknowledge the client's

discomfort and offer suggestions for managing the side effect, such as taking a mild analgesic or lying down in a dark room.

"We will ask the provider to prescribe a different medication for you." This statement is incorrect because it implies that nitroglycerin is not suitable for the client and may cause unnecessary anxiety or confusion. The nurse should explain that nitroglycerin is an effective and safe medication for angina and that the headache is a common and transient side effect that can be managed with simple measures. The nurse should also inform the client that there are other forms of nitroglycerin, such as patches or sprays, that may have less headache-inducing effects. However, changing the medication or the route of administration should be done only after consulting with the provider.

Right-sided heart failure is a condition in which the right ventricle fails to pump blood effectively to the lungs, causing a backup of blood in the systemic circulation. This leads to increased pressure in the right atrium and the vena cava, which can be measured by the central venous pressure (CVP). A normal CVP is 2 to 6 mm Hg, but in right-sided heart failure, it can rise above 10 mm Hg. Symptoms of right-sided heart failure include peripheral edema, jugular venous distension, hepatomegaly, ascites, and weight gain.

a. Increased pulmonary artery wedge pressure (PAWP). This statement is incorrect because it describes a finding of left-sided heart failure, not right-sided heart failure. Left-sided heart failure is a condition in which the left ventricle fails to pump blood effectively to the systemic circulation, causing a backup of blood in the pulmonary circulation. This leads to increased pressure in the left atrium and the pulmonary capillaries, which can be measured by the pulmonary artery wedge pressure (PAWP). A normal PAWP is 6 to 12 mm Hg, but in left-sided heart failure, it can rise above 18 mm Hg. Symptoms of left-sided heart failure include dyspnea, orthopnea, paroxysmal nocturnal dyspnea, crackles in the lungs, and pink frothy sputum.

c. Decreased brain natriuretic peptide (BNP). This statement is incorrect because it describes a finding of normal or reduced cardiac function, not heart failure. Brain natriuretic peptide (BNP) is a hormone secreted by the cardiac cells in response to increased stretch and pressure in the ventricles. It acts as a diuretic and a vasodilator, lowering blood volume and blood pressure. BNP is used as a biomarker for diagnosing and monitoring heart failure, as it reflects the degree of ventricular dysfunction. A normal BNP level is less than 100 pg/mL, but in heart failure, it can rise above 400 pg/mL.

d. Decreased specific gravity. This statement is incorrect because it describes a finding of dilute urine, not concentrated urine. Specific gravity is a measure of the concentration of solutes in urine, reflecting the ability of the kidneys to regulate fluid balance. A normal specific gravity is 1.005 to 1.030, but it can vary depending on fluid intake and output, hydration status, and renal function. In right-sided heart failure, fluid retention and reduced renal perfusion can cause oliguria and increased specific gravity of urine.