# A nurse is caring for a patient with acute kidney injury (AKI) who has developed severe hyperkalemia (K+ 7.2 mEq/L). The patient is experiencing cardiac arrhythmias. What is the nurse's priority intervention? > source: MyMerci (mymerci.kr) > url: https://mymerci.kr/pages/nclex_q.php?qn_id=541375 > language: ko > subject: Adult Health ## 문제 A nurse is caring for a patient with acute kidney injury (AKI) who has developed severe hyperkalemia (K+ 7.2 mEq/L). The patient is experiencing cardiac arrhythmias. What is the nurse's priority intervention? ## 보기 1. Administer IV calcium gluconate as prescribed **✔ 정답** 2. Prepare the patient for emergency hemodialysis 3. Administer sodium polystyrene sulfonate (Kayexalate) orally 4. Restrict potassium intake and monitor cardiac rhythm **정답: 1** ## 해설 IV calcium gluconate is the priority for immediate cardiac membrane stabilization in severe hyperkalemia with arrhythmias. Other options address potassium removal but do not provide immediate cardiac protection. ## 심화 해설 Clinical Priority Setting in Hyperkalemic Emergency The correct answer is Administer IV calcium gluconate as prescribed. In the context of a patient with acute kidney injury (AKI) presenting with severe hyperkalemia (K+ 7.2 mEq/L) and active cardiac arrhythmias, the immediate priority is to stabilize the myocardial cell membrane to prevent life-threatening cardiac arrest. Pathophysiology and Mechanism of Action The primary danger of severe hyperkalemia is its effect on the electrical conduction system of the heart. Elevated extracellular potassium alters the resting membrane potential of cardiac myocytes. Initially, this makes the cells more excitable, but as potassium levels continue to rise, the resting potential becomes less negative, inactivating sodium channels and slowing impulse conduction. This manifests on an ECG as peaked T-waves, loss of P-waves, widened QRS complexes, and eventually a sine-wave pattern that deteriorates into ventricular fibrillation or asystole [1]. The cardiac arrhythmias present in this patient indicate that this destabilization is already occurring. Intravenous calcium gluconate works immediately by antagonizing the effect of potassium on the myocardial cell membrane, raising the threshold potential and restoring a normal gradient between the resting and threshold potentials. This does not lower the serum potassium level, but it directly counteracts the cardiotoxic effects, making it the only intervention that provides immediate cardioprotection [2]. Why Other Options Are Not the Priority While the other interventions are essential components of hyperkalemia management, they do not provide the immediate cardiac stabilization required in an emergency. - Emergency hemodialysis is the most effective method for removing potassium from the body, especially in a patient with AKI whose kidneys are non-functional. However, even in an emergency, setting up dialysis takes time. During that preparation time, the patient’s unstable myocardium is vulnerable to fatal arrhythmias. Calcium must be administered first to protect the heart while dialysis arrangements are made [2]. - Sodium polystyrene sulfonate (Kayexalate) is a cation-exchange resin that removes potassium through the gastrointestinal tract. Its onset of action is slow, taking hours to significantly lower serum potassium levels. It has no role in the acute, minute-to-minute management of a life-threatening arrhythmia [2]. - Restricting potassium intake and monitoring cardiac rhythm is a fundamental nursing action for preventing worsening hyperkalemia, but it is not a treatment for an existing crisis. Continuous cardiac monitoring is crucial during and after the administration of calcium and other therapies, but it is a supportive measure, not the priority intervention to stop the immediate threat. Clinical Practice Integration For a patient with severe hyperkalemia and ECG changes or arrhythmias, the clinical sequence is clear. The nurse must first recognize that the arrhythmia represents an immediate threat of cardiac arrest. The priority action is to administer IV calcium gluconate or calcium chloride as prescribed to rapidly stabilize the cardiac membrane, an intervention supported by clinical guidelines for managing hyperkalemic emergencies [2]. Following this, therapies to shift potassium intracellularly (such as IV insulin and glucose) and to eliminate potassium from the body (such as hemodialysis) can be initiated. This case highlights the critical distinction between treatments that are temporizing and cardioprotective versus those that are definitive and potassium-lowering.References (research sources) - [1]Recognition and Management of Hyperkalemia-Induced Tachyarrhythmia in Pediatric Spontaneous Tumor Lysis Syndrome: A Simulation Case.Research articleSoliman YH, Kochhar M, Petrone G, Wing R, Sojar SH. (2026) · DOI: 10.7759/cureus.107494 - [2]Management of hyperkalemia in patients with kidney disease: a position paper endorsed by the Italian Society of Nephrology.Research articleBianchi S, Aucella F, De Nicola L, Genovesi S, Paoletti E, Regolisti G. (2019) · DOI: 10.1007/s40620-019-00617-y ## 임상 시나리오 Hyperkalemic Emergency in AKIPrioritizing Immediate Cardioprotection In a patient with acute kidney injury and severe hyperkalemia (K+ 7.2 mEq/L) with cardiac arrhythmias, the priority is to antagonize the cardiotoxic effects. Administer IV calcium gluconate first to stabilize the myocardial cell membrane. Calcium does not lower serum potassium but raises the threshold potential, restoring normal electrical conduction. ECG changes in hyperkalemia progress from peaked T-waves to a widened QRS and a sine-wave pattern, which can rapidly deteriorate into ventricular fibrillation. CautionDo not delay cardioprotection for potassium-removal therapies like hemodialysis or Kayexalate. These are secondary interventions that work too slowly to prevent an imminent cardiac arrest. ## 핵심 개념 - **Calcium Gluconate** — An IV medication that antagonizes the cardiotoxic effects of hyperkalemia by stabilizing the myocardial cell membrane without lowering serum potassium levels. - **Resting Membrane Potential** — The electrical potential difference across the cell membrane at rest; elevated extracellular potassium makes this less negative, leading to cardiac instability. - **Sine-wave Pattern** — A critical ECG finding in severe hyperkalemia characterized by a wide, undulating baseline that often precedes ventricular fibrillation or asystole. - **Sodium Polystyrene Sulfonate** — A cation-exchange resin that removes potassium through the gastrointestinal tract but works too slowly for emergency management of cardiac arrhythmias. - **Acute Kidney Injury** — A sudden episode of kidney failure or damage that impairs the excretion of electrolytes like potassium, leading to life-threatening imbalances. ## 같은 주제 문제 - [A nurse is assessing a patient with suspected acute kidney injury (AKI). 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