A nurse is caring for a client who has an infection and is starting to take gentamicin. Which of the following client laboratory tests should the nurse monitor to detect an adverse effect of the medication?

Choice A rationale B-type natriuretic peptide (BNP) is a hormone produced by the heart and is a key indicator of heart failure. Elevated BNP levels signal increased ventricular stretch and pressure. Gentamicin, an aminoglycoside antibiotic, does not typically exert a cardiotoxic effect that would significantly alter BNP levels, making it an unreliable marker for monitoring its adverse effects. Choice B rationale Gentamicin is a known nephrotoxic medication. The kidneys are responsible for filtering blood and excreting waste products. Gentamicin can accumulate in the renal tubules, leading to tubular necrosis and reduced glomerular filtration rate. Monitoring creatinine levels, a byproduct of muscle metabolism and a key indicator of kidney function (normal range 0.6-1.2 mg/dL), is therefore essential to detect early kidney damage. Choice C rationale Amylase is an enzyme primarily produced by the pancreas and salivary glands, playing a crucial role in carbohydrate digestion. Elevated amylase levels (normal range 25-125 U/L) are a hallmark of pancreatitis. Gentamicin does not have a known adverse effect on the pancreas and is not associated with causing pancreatitis or affecting amylase levels. Choice D rationale Erythrocyte sedimentation rate (ESR) is a non-specific measure of inflammation in the body. It indicates how quickly red blood cells settle in a test tube and is elevated in various inflammatory conditions. While gentamicin treats infections that cause inflammation, it does not have a direct effect on the ESR and is not a specific marker for its own adverse effects.