A nurse is reviewing the medication list of a patient with end-stage renal disease (ESRD) who is receiving hemodialysis. The nurse knows that certain medications are used to prevent complications of this disease. Which of the following medications would the nurse question as part of routine therapy for preventing complications of ESRD?

Choice A reason: In the oliguric phase of AKI, kidney function is severely impaired, reducing potassium excretion. This leads to hyperkalemia, which disrupts cardiac electrical activity, potentially causing life-threatening arrhythmias or cardiac arrest. Elevated potassium levels are a hallmark of this phase due to decreased glomerular filtration rate and impaired tubular secretion.

Choice B reason: Urine output of 2000 mL in 24 hours indicates polyuria, characteristic of the recovery phase of AKI, not the oliguric phase, where output is typically less than 400 mL/day. High urine output suggests restored renal function, which is not expected in the oliguric phase, where kidneys fail to filter adequately.

Choice C reason: Tachycardia may occur in AKI due to fluid overload causing increased cardiac workload or electrolyte imbalances like hyperkalemia affecting heart rhythm. However, it is a secondary symptom and less specific than hyperkalemia, which directly results from impaired renal excretion and poses a more immediate risk to cardiac function.

Choice D reason: Tenting of the skin indicates dehydration, which may precede AKI but is not typical in the oliguric phase, where fluid retention is more common due to reduced urine output. Fluid overload leads to edema, not dehydration, making skin tenting an unlikely finding in this phase of AKI.

Choice A reason: Left-sided flank pain may suggest kidney stones or infection but is not specific to AKI. Pain can occur in various conditions, including pyelonephritis or ureteral obstruction, and does not directly indicate reduced glomerular filtration or oliguria, which are hallmarks of AKI, making it less urgent.

Choice B reason: Blood pressure of 138/86 mm Hg and heart rate of 92 bpm are within normal ranges and not specific to AKI. While hypertension can occur in AKI due to fluid overload, these values do not strongly suggest AKI without other signs like oliguria or lab abnormalities.

Choice C reason: Cloudy urine with sediment and foul odor suggests a urinary tract infection, not necessarily AKI. Infections can coexist with AKI but are not diagnostic. AKI is characterized by reduced urine output and elevated creatinine, not primarily by urine appearance, making this finding less indicative.

Choice D reason: Urine output of 150 mL in 8 hours (450 mL/day) indicates oliguria, a key sign of AKI, where kidneys fail to filter adequately, reducing urine production. This can lead to fluid overload and toxin accumulation, necessitating urgent provider notification to evaluate and manage potential AKI complications like hyperkalemia.