The nurse is caring for a patient who has been vomiting and has diarrhea for 3 days and now has muscle weakness and paresthesias in his hands and feet, along with an irregular pulse rate and rhythm, and shallow respirations with crackles on auscultation of his lungs bilaterally. The nurse suspects that these symptoms are most likely due to which electrolyte imbalance?

Choice A reason:

The client reports increased thirst. This is not an indication that the medication was effective, because increased thirst can be a sign of dehydration or electrolyte imbalance caused by excessive diuresis. Furosemide can cause loss of water and sodium, potassium, calcium, magnesium, and chloride in the urine.

Choice B reason:

The client's urine output is 250 mL/hr. This is an indication that the medication was effective, because furosemide is a loop diuretic that inhibits the reabsorption of sodium and water in the ascending limb of the loop of Henle, resulting in increased urine output and decreased fluid volume. A normal urine output is about 30 to 60 mL/hr, so a urine output of 250 mL/hr indicates a significant diuretic effect.

Choice C reason:

The client's heart rate is 100/min. This is not an indication that the medication was effective, because a high heart rate can be a sign of hypovolemia, hypotension, or cardiac stress caused by furosemide. Furosemide can lower the blood pressure and reduce the preload and afterload on the heart, but it can also trigger compensatory mechanisms such as increased sympathetic activity and renin-angiotensin-aldosterone system activation, which can increase the heart rate.

Choice D reason:

The client's weight is unchanged. This is not an indication that the medication was effective, because weight loss is expected with furosemide therapy due to fluid removal. Furosemide can cause a rapid and significant reduction in fluid volume, which can be measured by daily weight changes. A weight loss of 1 kg corresponds to a fluid loss of about 1 L.

Choice A reason: This is incorrect because 0.9% sodium chloride (normal saline) is an isotonic solution, not a hypotonic one. Isotonic solutions have the same concentration of solutes as blood plasma and do not cause fluid movement across the cell membrane.

Choice B reason:

This is incorrect because 0.9% sodium chloride (normal saline) is an isotonic solution, not a hypertonic one. Hypertonic solutions have a higher concentration of solutes than blood plasma and cause fluid to move out of the cells and into the vascular space.

Choice C reason:

This is correct because 0.9% sodium chloride (normal saline) is an isotonic solution that will expand the vascular space by adding fluid without changing the concentration of solutes. This is useful for patients with hyponatremia (low sodium level in the blood) who need to restore their fluid and electrolyte balance.

Choice D reason:

This is incorrect because 0.9% sodium chloride (normal saline) is an isotonic solution that will expand the vascular space by adding fluid without changing the concentration of solutes. It will not have no effect on fluid movement, as it will increase the intravascular volume.