A nurse in an emergency department is assessing a client who was biten on the left leg by a poisonous snake. The client has placed elastic bandages snugly above and below the bite marks and is in no apparent distress. Which of the following actions should the nurse take?

Choice A: Carvedilol is not a medication that interacts with contrast material and places the client at risk for acute kidney injury. Carvedilol is a beta-blocker that lowers blood pressure and heart rate by blocking the effects of adrenaline on the heart and blood vessels. Carvedilol does not affect kidney function or contrast excretion, but it can cause hypotension, bradycardia, or heart failure in some clients.

Choice B: Nitroglycerin is not a medication that interacts with contrast material and places the client at risk for acute kidney injury. Nitroglycerin is a vasodilator that relaxes the smooth muscles of the blood vessels and increases blood flow to the heart. Nitroglycerin does not affect kidney function or contrast excretion, but it can cause hypotension, headache, or flushing in some clients.

Choice C: Atorvastatin is not a medication that interacts with contrast material and places the client at risk for acute kidney injury. Atorvastatin is a statin that lowers cholesterol levels by inhibiting an enzyme that produces cholesterol in the liver. Atorvastatin does not affect kidney function or contrast excretion, but it can cause liver damage, muscle pain, or rhabdomyolysis in some clients.

Choice D: Metformin is a medication that interacts with contrast material and places the client at risk for acute kidney injury. Metformin is an oral antidiabetic drug that lowers blood glucose levels by decreasing hepatic glucose production and increasing insulin sensitivity. Metformin can accumulate in the kidneys and cause lactic acidosis, a life-threatening condition characterized by high levels of lactic acid in the blood. Contrast material can worsen kidney function and increase the risk of lactic acidosis in clients taking metformin. Therefore, metformin should be discontinued before and after the procedure as prescribed.

Choice A Reason: This is incorrect because these values indicate respiratory alkalosis, which is caused by hyperventilation or excess loss of carbon dioxide (PaCO2). Respiratory alkalosis increases the blood pH and decreases the HCO3- level.

Choice B Reason: This is incorrect because these values indicate metabolic alkalosis, which is caused by excess intake or retention of bases or loss of acids. Metabolic alkalosis increases the blood pH and the HCO3- level.

Choice C Reason: This is incorrect because these values indicate respiratory acidosis, which is caused by hypoventilation or excess retention of carbon dioxide (PaCO2). Respiratory acidosis decreases the blood pH and increases the HCO3- level.

Choice D Reason: This is correct because these values indicate metabolic acidosis, which is a common complication of chronic kidney disease. These values indicate metabolic acidosis, which is a common complication of chronic kidney disease. Metabolic acidosis occurs when the kidneys are unable to excrete excess acids or retain enough bicarbonate (HCO3-), which is a base that buffers the blood pH. As a result, the blood pH decreases and becomes more acidic. The normal range for blood pH is 7.35 to 7.45, for HCO3- is 22 to 26 mEq/L, and for PaCO2 is 35 to 45 mm Hg.