Mannitol administration can lead to which complication?

• A. Hyperkalemia
• B. Pulmonary edema
• C. Hypoglycemia
• D. Hepatotoxicity

Answer: (B)

Mannitol acts as an osmotic agent, drawing water from cells into the intravascular space and then being excreted by the kidneys. This osmotic effect can expand extracellular volume, and if the infusion is rapid or the patient has limited cardiac or renal reserve, the resulting fluid overload can overwhelm the lungs, causing pulmonary edema. This is a well-recognized complication, especially in patients with heart failure or renal impairment, and it often presents with dyspnea, crackles on exam, and hypoxemia.

Hyperkalemia, hypoglycemia, and hepatotoxicity are not typical complications of mannitol administration. Mannitol’s main risks are related to fluid and electrolyte balance, and the potential for pulmonary edema if the osmotic load cannot be excreted adequately.