A patient develops acute renal failure after receiving a nephrotoxic antibiotic and has a 24-hour urine output of 240 mL. The nurse suspects risk for which condition?

• A. Cardiac arrhythmia
• B. Paresthesia
• C. Dehydration
• D. Pruritus

Answer: (A)

Oliguria in acute renal failure signals that the kidneys aren’t excreting waste and electrolytes effectively. A 24-hour urine output of 240 mL is low enough to be considered oliguric, which means potassium is likely not being cleared adequately. That buildup can lead to hyperkalemia, a dangerous state that directly affects heart rhythm and can cause potentially life-threatening cardiac arrhythmias. So the most important risk to monitor and intervene for is a cardiac rhythm disturbance due to high potassium.

Paresthesias can occur with electrolyte imbalances, but they are not the immediate, life-threatening concern in this presentation. Dehydration implies volume loss, which isn’t the primary issue here since the problem is reduced excretion rather than loss of fluids. Pruritus can occur with uremia, but it’s more a symptom of prolonged kidney failure rather than the acute risk posed by oliguria in this scenario.