The client is scheduled to receive 30 grams of lactulose orally every 12 hours. An oral solution containing 5 g/10 mL is available. How many mL should be poured into the medication cup to administer the required dose?

Choice A: Troponin Troponin levels increase within 3-12 hours from the onset of chest pain, peak at 24-48 hours, and return to baseline over 5-14 days. Troponin is a protein found in cardiac muscle fibers that regulates muscular contraction. When heart muscle is damaged, as in the case of an MI, troponin is released into the bloodstream. The elevation of troponin levels is a key indicator of myocardial infarction and can be used to diagnose and assess the extent of heart muscle damage. Troponin is the most reliable laboratory value that is expected to be elevated following a myocardial infarction, making it the correct choice in this scenario.

Choice B: Aspartate aminotransferase (AST) AST is an enzyme found in high concentrations in the liver, heart, muscles, kidneys, and brain. It is released into the bloodstream when any of these tissues are damaged. While AST can be elevated in cases of MI, it is not as specific as troponin because it is present in many other tissues besides the heart.

Choice C: Serum amylase Serum amylase is an enzyme that helps digest carbohydrates and is primarily associated with the pancreas and salivary glands. Its elevation is not specifically related to myocardial infarction but can be seen in other conditions such as pancreatitis.

Choice D: Unconjugated bilirubin Unconjugated bilirubin is a breakdown product of hemoglobin from red blood cells. Elevated levels of unconjugated bilirubin are typically associated with conditions affecting the liver or the breakdown of red blood cells, not myocardial infarction.

Choice A reason: Anorexia, or loss of appetite, is not typically a direct manifestation of left-sided heart failure. While it can be associated with many medical conditions and may occur in the context of heart failure due to overall decreased well-being, it is not a specific indicator of left-sided heart failure.

Choice B reason: Weight gain can be associated with heart failure, but it is more commonly a sign of right-sided heart failure, where fluid accumulates in the body tissues, causing swelling and weight increase. In left-sided heart failure, weight gain is not as prominent because the primary issue is the backup of blood into the lungs, not fluid retention in the tissues.

Choice C reason: A distended abdomen can occur in heart failure due to fluid accumulation; however, it is more characteristic of right-sided heart failure, where the failure of the right ventricle leads to systemic congestion, including the abdominal area. In left-sided heart failure, the primary effect is on the lungs, not the abdomen.

Choice D reason: Dyspnea, or difficulty breathing, is a hallmark symptom of left-sided heart failure. It occurs due to the backup of blood in the pulmonary circulation, which leads to pulmonary congestion and reduced oxygen exchange. Patients may experience shortness of breath, especially during exertion or when lying flat (orthopnea), and may wake up at night with shortness of breath (paroxysmal nocturnal dyspnea).

Left-sided heart failure, often caused by conditions like valvular heart disease, leads to a decrease in the heart’s ability to pump blood effectively. This results in a buildup of pressure in the lungs, manifesting as dyspnea, which is an important symptom for nurses and other healthcare providers to recognize and manage promptly.