A nurse is caring for a patient with acute lymphoblastic leukemia who develops tumor lysis syndrome. The patient's laboratory results show: potassium 6.8 mEq/L, phosphorus 8.2 mg/dL, calcium 7.1 mg/dL, and uric acid 12.5 mg/dL. Which nursing intervention should be the priority?

Tumor lysis syndrome with severe hyperkalemia (6.8 mEq/L), hyperphosphatemia, hypocalcemia, and hyperuricemia requires immediate hemodialysis to prevent life-threatening cardiac arrhythmias and acute kidney injury. Other options address specific imbalances but do not correct all simultaneously.

Understanding the Clinical Scenario
The patient has acute lymphoblastic leukemia and has developed tumor lysis syndrome (TLS). The laboratory values indicate severe metabolic derangements: a critically high potassium level of 6.8 mEq/L, hyperphosphatemia at 8.2 mg/dL, hypocalcemia at 7.1 mg/dL, and severe hyperuricemia at 12.5 mg/dL. These findings represent a life-threatening oncologic emergency.

Priority Nursing Intervention and Rationale
The correct answer is to prepare for emergency hemodialysis and notify the nephrologist. The priority in TLS management is determined by the immediate threat to life. The serum potassium of 6.8 mEq/L places this patient at extreme risk for a fatal cardiac arrhythmia. While all the listed interventions are components of TLS management, the severity and combination of electrolyte disturbances, particularly the hyperkalemia, make hemodialysis the definitive and most urgent treatment to rapidly correct these abnormalities. As noted in the simulation case by Soliman et al., prompt recognition and treatment of hyperkalemia-induced arrhythmias in TLS is vital, as these can be life-threatening, potentially leading to renal failure, arrhythmias, or multi-organ failure ^[1].

Analysis of the Intervention Options
- Administer calcium gluconate IV push: This is a temporizing measure that stabilizes the cardiac membrane against the effects of hyperkalemia but does not lower the serum potassium level. It is an important step, but it is not the definitive priority over arranging for definitive potassium removal in a patient with multi-electrolyte disturbances from TLS.
- Prepare for emergency hemodialysis: This is the priority. Hemodialysis is the most rapid and effective method for removing potassium, phosphorus, and uric acid from the blood, while also correcting acidosis. The presence of severe hyperkalemia, hyperphosphatemia, and hyperuricemia that is refractory to medical management or causing acute kidney injury makes this the definitive, life-saving intervention.
- Increase IV fluid rate: Aggressive IV hydration is a cornerstone of TLS prevention and management, primarily to promote renal excretion of uric acid and phosphorus. However, in the setting of established severe hyperkalemia and potential renal dysfunction, this intervention is too slow and insufficient to address the immediate cardiac threat.
- Administer allopurinol: Allopurinol reduces the production of new uric acid by inhibiting xanthine oxidase. It is a preventative measure and does not treat pre-existing hyperuricemia or the other life-threatening electrolyte imbalances already present. Its effect is not immediate and does not address the critical hyperkalemia.

Clinical Integration and System-Level Evidence
The urgency of this scenario is supported by real-world data on hyperkalemia management. A large retrospective study by Lyu et al. demonstrated that a standardized hyperkalemia management system significantly improved rates of diagnosis, treatment, and review . This underscores that hyperkalemia is a critical finding requiring a systematic and rapid response. The study found that in routine care, treatment rates were only 58.29%, highlighting a dangerous gap in care that a standardized, protocol-driven approach—like the one a nurse initiates by preparing for emergency hemodialysis—is designed to close . The nurse’s priority action of recognizing the severity and mobilizing the definitive therapy (hemodialysis) is the clinical application of this system-level principle, ensuring the patient receives the highest level of timely intervention to prevent a cardiac arrest.