Certified Medical-Surgical Registered Nurse Practice Exam

After administering mannitol, a nurse should monitor for which potential side effect?

1. Hyperglycemia

2. Electrolyte imbalance

3. Hypotension

4. Fluid overload

The correct answer is: Electrolyte imbalance

When administering mannitol, it is crucial to monitor for electrolyte imbalance because mannitol is an osmotic diuretic that works by drawing fluid into the intravascular space, which can lead to changes in electrolyte concentrations. This medication can cause increased urine output, leading to potential losses of electrolytes such as sodium and potassium. Additionally, the rapid shift of fluids can also disturb normal electrolyte balance, resulting in conditions like hypernatremia or hypokalemia. While other side effects like hyperglycemia, hypotension, and fluid overload can occur under certain circumstances, they are not as directly related to the mechanism of action of mannitol compared to electrolyte imbalance. Hyperglycemia is more commonly associated with other medications, especially certain diuretics or conditions. Hypotension may occur due to volume depletion but is not a primary concern with mannitol. Fluid overload is more of a risk in patients with renal impairment or if mannitol is administered excessively rather than a routine side effect. Thus, monitoring for electrolyte imbalance is a critical nursing consideration following mannitol administration.