Megan's patient is on strict intake and output measurements. Her patient's total output is 2200 mL. What should the total intake be for an average adult?

Choice A reason: This is correct because 3.5 to 5.0 mEq/L is the normal range of serum potassium level in adults. Potassium is an electrolyte that is important for nerve and muscle function, as well as acid-base balance.

Choice B reason: This is incorrect because 8.5 to 10.5 mg/dL is the normal range of serum calcium level in adults, not potassium. Calcium is an electrolyte that is involved in bone health, muscle contraction, and blood clotting.

Choice C reason: This is incorrect because 135 to 145 mEq/L is the normal range of serum sodium level in adults, not potassium. Sodium is an electrolyte that is essential for fluid balance, nerve transmission, and muscle contraction.

Choice D reason: This is incorrect because 1.8 to 2.6 mEq/L is the normal range of serum magnesium level in adults, not potassium. Magnesium is an electrolyte that is important for muscle and nerve function, as well as enzyme activity.

Choice A reason: Kidney function is not indicated by the PaCO2 level, but rather by the creatinine and blood urea nitrogen (BUN) levels. The kidneys are responsible for regulating the HCO3- level, which is the other component of the carbonic acid-bicarbonate buffer system.

Choice B reason: Bicarbonate buffers are not indicated by the PaCO2 level, but rather by the HCO3- level. Bicarbonate buffers are substances that can accept or donate hydrogen ions to maintain the pH of the blood. They are part of the carbonic acid-bicarbonate buffer system, which is the main buffer system in the body.

Choice C reason: Phosphate buffers are not indicated by the PaCO2 level, but rather by the PO4^3^- level. Phosphate buffers are substances that can accept or donate hydrogen ions to maintain the pH of the intracellular fluid and the urine. They are part of the phosphoric acid-phosphate buffer system, which is the second most important buffer system in the body.

Choice D reason: Lung ventilation is indicated by the PaCO2 level, which is the partial pressure of carbon dioxide in the blood. Lung ventilation is the process of moving air in and out of the lungs, which affects the amount of carbon dioxide exhaled. The lungs are responsible for regulating the PaCO2 level, which is the other component of the carbonic acid-bicarbonate buffer system.