A nurse is caring for a client who has metabolic acidosis and is receiving sodium bicarbonate IV bolus and infusion to correct the pH imbalance. Which of the following laboratory values should the nurse monitor to evaluate the effectiveness of the therapy?

Choice A: Decreased serum pH. This is incorrect because hypokalemia usually causes increased serum pH, not decreased. This is because low potassium levels can lead to metabolic alkalosis, a condition where the blood is too alkaline due to loss of acid from the body. This can happen in cases of vomiting, diuretic use, or mineralocorticoid excess.

Choice B:

Increased serum calcium. This is incorrect because hypokalemia does not directly affect serum calcium levels. However, hypokalemia can cause hypomagnesemia, or low magnesium levels, which can in turn cause hypercalcemia, or high calcium levels. This is because magnesium is needed for the secretion of parathyroid hormone (PTH), which regulates calcium balance in the body. Low magnesium levels can lead to increased PTH secretion and increased calcium reabsorption from the bones and kidneys.

Choice C:

Decreased serum magnesium. This is correct because hypokalemia and hypomagnesemia often occur together, especially in cases of chronic diarrhea, malabsorption, alcoholism, or diuretic use. This is because potassium and magnesium are both lost in the urine or stool when these conditions are present. Hypomagnesemia can also cause hypokalemia by impairing the reabsorption of potassium in the kidneys and increasing the entry of potassium into the cells.

Choice D:

Increased serum bicarbonate. This is incorrect because hypokalemia usually causes decreased serum bicarbonate, not increased. This is because low potassium levels can lead to metabolic acidosis, a condition where the blood is too acidic due to accumulation of acid in the body. This can happen in cases of diabetic ketoacidosis, renal tubular acidosis, or chronic kidney disease.

Choice A reason:

Hypernatremia is not a likely complication of fluid therapy for diabetic ketoacidosis (DKA) Hypernatremia occurs when there is a loss of water or an excess of sodium in the body. Fluid therapy for DKA usually involves normal saline and dextrose, which do not cause hypernatremia. In fact, fluid therapy may help correct the dehydration and hyperosmolality that are associated with DKA.

Choice B reason:

Hyperkalemia is also not a likely complication of fluid therapy for DKA. Hyperkalemia occurs when there is an excess of potassium in the blood. Fluid therapy for DKA usually involves insulin infusion, which helps lower the potassium level by driving it into the cells. Insulin also helps lower the blood glucose level and reverse the acidosis that are characteristic of DKA.

Choice C reason:

Fluid volume deficit is a common manifestation of DKA, not a complication of fluid therapy. Fluid volume deficit occurs when there is a loss of fluid and electrolytes from the body due to osmotic diuresis, vomiting, and increased respiratory rate. Fluid therapy for DKA aims to restore the fluid volume and correct the electrolyte imbalances that result from fluid loss.

Choice D reason:

Cerebral edema is a potential complication of fluid therapy for DKA, especially in children and young adults. Cerebral edema occurs when there is an increase in intracranial pressure due to swelling of the brain tissue. Fluid therapy for DKA may cause cerebral edema by altering the osmotic gradient between the blood and the brain, leading to fluid shifts into the brain cells. Cerebral edema can cause neurological symptoms such as headache, confusion, seizures, and coma.