Which laboratory results should the nurse closely monitor in a client who has end-stage renal disease (ESRD)?

Choice A reason: Blood pressure, heart rate, and temperature are vital signs that should be monitored in any client, but they are not laboratory results. ESRD can cause hypertension and cardiovascular complications, so blood pressure and heart rate should be controlled with medications and lifestyle modifications. Temperature should be monitored for signs of infection or inflammation.

Choice B reason: Leukocytes, neutrophils, and thyroxine are not specific laboratory results for ESRD. Leukocytes and neutrophils are types of white blood cells that indicate immune system activity and infection. Thyroxine is a thyroid hormone that regulates metabolism and growth. ESRD can affect the immune system and the thyroid function, but these are not the primary indicators of renal function.

Choice C reason: This is the correct answer because serum potassium, calcium, and phosphorus are important laboratory results for ESRD. ESRD can cause electrolyte imbalances that can affect the heart, muscles, nerves, and bones. Serum potassium can increase due to reduced renal excretion and cause cardiac arrhythmias and muscle weakness. Serum calcium can decrease due to impaired absorption and activation of vitamin D and cause muscle cramps, tetany, and osteoporosis. Serum phosphorus can increase due to reduced renal excretion and cause soft tissue calcification and bone pain.

Choice D reason: Erythrocytes, hemoglobin, and hematocrit are laboratory results that measure red blood cell count, oxygen-carrying capacity, and blood volume. ESRD can cause anemia due to reduced production of erythropoietin, a hormone that stimulates red blood cell formation in the bone marrow. Anemia can cause fatigue, pallor, shortness of breath, and chest pain. However, these are not the most significant laboratory results for ESRD.

Choice A reason: Administering a half dose now is not advisable, because it may result in underdosing or overdosing of digoxin. Digoxin has a narrow therapeutic range and a high risk of toxicity, especially in infants and children. The amount of digoxin absorbed by the infant before vomiting is unknown, so giving a partial dose may not achieve therapeutic levels or may exceed safe levels.

Choice B reason: Giving another dose is not advisable, because it may result in overdosing of digoxin. Digoxin has a narrow therapeutic range and a high risk of toxicity, especially in infants and children. The amount of digoxin absorbed by the infant before vomiting is unknown, so giving a full dose may exceed safe levels and cause adverse effects such as nausea, vomiting, bradycardia, arrhythmias, or visual disturbances.

Choice C reason: Mixing the next dose with food is not advisable, because it may affect the absorption and bioavailability of digoxin. Digoxin should be taken on an empty stomach or at least one hour before or two hours after meals, because food can interfere with its absorption from the gastrointestinal tract and reduce its effectiveness.

Choice D reason: Withholding this dose is the best instruction for the nurse to provide to this mother. Digoxin has a long half-life and accumulates in tissues, so missing one dose will not significantly affect its therapeutic effect. Withholding this dose will avoid overdosing and toxicity of digoxin, which can be life-threatening in infants and children. The nurse should also advise the mother to resume the regular dosing schedule and monitor the infant's pulse rate and signs of digoxin toxicity.