A nurse is caring for a client with stage 5 chronic kidney disease (CKD) who has developed hyperkalemia. Which nursing intervention should the nurse implement first?

For severe hyperkalemia (K+ 6.8 mEq/L), the priority is to obtain an immediate ECG to assess for life-threatening cardiac dysrhythmias, as hyperkalemia can cause fatal complications. Other interventions like Kayexalate or hemodialysis are important but follow cardiac assessment.

Understanding the Priority: Safety and the Nursing Process

In a client with stage 5 chronic kidney disease (CKD), the kidneys have lost nearly all ability to excrete potassium, creating a constant risk for hyperkalemia. When hyperkalemia is identified, the immediate threat is not the elevated lab value itself, but the potential for life-threatening cardiac conduction disturbances. The nursing process dictates that assessment must come before intervention. Before administering any medication, preparing for dialysis, or implementing dietary teaching, the nurse must first determine the physiological impact of the high potassium level on the myocardium. A 12-lead electrocardiogram (ECG) provides this critical, real-time assessment data.

Why the ECG is the First Priority

Hyperkalemia depolarizes cardiac cell membranes, which slows conduction and alters the action potential. This can manifest on the ECG in a typically progressive, but not always predictable, manner. The earliest sign may be peaked T-waves, which can deteriorate into a widened QRS complex, and eventually into a sine-wave pattern and cardiac arrest. However, the provided evidence underscores a crucial clinical point: the absence of ECG changes does not rule out severe hyperkalemia, but the presence of certain patterns demands immediate action. The case described by Tahir et al. ^[2] involved a patient with a serum potassium of 8.7 mmol/L who presented with no ECG abnormalities. This demonstrates that a "normal" ECG provides a false sense of security only if it is not obtained; you must first look to know the rhythm status. Conversely, the cases by Achuta et al. ^[1] and Abdi et al. ^[4] show the other end of the spectrum, where hyperkalemia in missed-dialysis patients triggered BRASH syndrome and complete atrioventricular (AV) block with a ventricular escape rhythm of only 15-20 beats per minute. These rhythm findings directly dictate the next steps in management, such as the urgent administration of calcium gluconate to stabilize the cardiac membrane or emergency pacing. Without the ECG, the nurse is intervening blindly.

Analyzing the Other Options in the Context of Priority

- Administer sodium polystyrene sulfonate (Kayexalate) as ordered: This is an intervention to lower total body potassium by exchanging sodium for potassium in the gut. Its action is slow, taking hours to have an effect. It does nothing to antagonize the immediate cardiotoxic effects of potassium that is already circulating. This is an appropriate long-term management strategy but is not the first action for an acutely dangerous level .

- Prepare the client for emergency hemodialysis: Hemodialysis is the most effective method for removing potassium from the body and is a definitive treatment, especially in anuric stage 5 CKD patients who have missed dialysis, a classic trigger for BRASH syndrome ^[1]. However, preparing for dialysis is a process that takes time. The immediate priority is to assess cardiac stability and initiate membrane-stabilizing therapies if the ECG is abnormal. Dialysis preparation follows the initial assessment and emergency measures.

- Restrict dietary potassium intake to less than 2 grams per day: Dietary education is a crucial, long-term preventive strategy for managing chronic hyperkalemia in CKD, particularly to allow for continued use of renin-angiotensin-aldosterone system inhibitors (RAASi) . However, dietary restriction has no role in the acute management of a dangerously high potassium level. It is an inappropriate and ineffective first action when the client is at immediate risk for a fatal arrhythmia.

The correct sequence begins with obtaining the 12-lead ECG to assess for cardiotoxic effects. If the ECG shows signs of hyperkalemia (e.g., peaked T-waves, loss of P-waves, widened QRS), the nurse would then anticipate an order for intravenous calcium to stabilize the myocardium, followed by therapies to shift potassium intracellularly (e.g., insulin and glucose) and finally to remove potassium from the body (e.g., dialysis or a potassium binder) [1,4].