A nurse is caring for a client who is receiving IV fluids to correct dehydration. Which of the following laboratory values should indicate to the nurse that the client is effectively responding to treatment?

Choice A: Concentrated hemoglobin and hematocrit levels are not a sign of fluid volume overload, but rather of fluid volume deficit. This is a condition that occurs when the body loses more fluid than it gains. This can happen in patients who have excessive bleeding, vomiting, diarrhea, or diaphoresis. Concentrated hemoglobin and hematocrit levels indicate hemoconcentration, which is an increase in the ratio of blood cells to plasma.

Choice B: Distended neck veins are a sign of fluid volume overload, because this condition occurs when the body retains more fluid than it excretes. This can happen in patients who have heart failure, kidney failure, or excessive fluid intake. Distended neck veins indicate increased central venous pressure, which is a measure of the pressure in the right atrium of the heart.

Choice C: Decreased urine output is not a sign of fluid volume overload, but rather of oliguria or anuria. These are conditions that occur when the urine output is less than 400 mL or 50 mL per day, respectively. These can happen in patients who have acute or chronic kidney injury, urinary obstruction, or shock. Decreased urine output indicates impaired renal function and decreased glomerular filtration rate.

Choice D: Poor skin turgor is not a sign of fluid volume overload, but rather of dehydration. This is a condition that occurs when the body loses more water than it gains. This can happen in patients who have fever, diabetes insipidus, or hyperglycemia. Poor skin turgor indicates decreased skin elasticity and delayed return to normal shape after being pinched.

Choice A Reason: This is incorrect because effects of rapidly infused intravenous fluids are not the cause of the patient's findings, but a possible treatment. Rapidly infused intravenous fluids are used to restore fluid volume and prevent shock in patients with fluid volume deficit. Rapidly infused intravenous fluids can cause increased blood pressure, increased urine output, and decreased heart rate.

Choice B Reason: This is correct because the body's natural compensatory mechanisms are the cause of the patient's findings. The body tries to maintain homeostasis and perfusion in response to fluid volume deficit by activating the sympathetic nervous system, the renin-angiotensin-aldosterone system, and the antidiuretic hormone system. These mechanisms cause tachycardia, vasoconstriction, pale and cool skin, sodium and water retention, and decreased urine output.

Choice C Reason: This is incorrect because cardiac failure is not the cause of the patient's findings, but a possible complication. Cardiac failure occurs when the heart is unable to pump enough blood to meet the body's needs. Cardiac failure can result from prolonged fluid volume deficit, as the heart becomes overstressed and weakened by the increased workload and decreased perfusion. Cardiac failure can cause dyspnea, edema, fatigue, and cyanosis.

Choice D Reason: This is incorrect because pharmacological effects of a diuretic are not the cause of the patient's findings, but a possible cause of fluid volume deficit. A diuretic is a medication that increases urine output and excretion of sodium and water. A diuretic can cause fluid volume deficit if it is overdosed, misused, or taken with other medications that affect fluid balance. A diuretic can cause hypotension, dehydration, and electrolyte imbalances.