What is the most critical nursing action for a patient in the polyureic stage of acute tubular necrosis (ATN)?

In the polyuric stage of acute tubular necrosis (ATN), patients experience significant urine output, which can lead to the risk of dehydration and electrolyte imbalances. This phase is characterized by increased urine production as the kidneys begin to recover, but their ability to concentrate urine remains impaired. Consequently, monitoring electrolyte levels and signs of fluid depletion becomes paramount.

By closely observing electrolyte levels, healthcare professionals can identify potential complications like hyperkalemia or hypocalcemia that may arise from renal dysfunction. Additionally, signs of fluid depletion such as low blood pressure or increased heart rate can indicate that the patient needs intervention to replace lost fluids effectively. Therefore, prioritizing these assessments allows for timely interventions that can prevent serious complications and aid in the patient's recovery.

Other options, although important in the management of a patient with ATN, do not capture the immediate critical need during the polyuric phase. Administering intravenous fluids, assessing urine output, and providing nutritional support are relevant actions, but they all stem from the foundational need to monitor the patient’s status to ensure that any necessary adjustments are made proactively.