The patient is getting potassium correction in 5% dextrose. What ECG changes will the nurse see to stop the infusion?

Appeared in: NORCET 1 - 2020

Explanation

Potassium correction infusions are administered to treat hypokalemia but carry the risk of causing iatrogenic hyperkalemia (high potassium).
The earliest and most characteristic ECG sign of hyperkalemia is the development of tall, peaked (or 'tented') T waves.
This change reflects altered ventricular repolarization and is a critical warning sign that the infusion must be stopped immediately to prevent life-threatening cardiac arrhythmias.

Option A: A prominent U wave is a classic ECG finding in hypokalemia (low potassium), the very condition being treated.
Option C: ST segment depression is typically associated with hypokalemia or myocardial ischemia, not the initial stages of hyperkalemia.
Option D: Shallow or flattened T waves are characteristic of hypokalemia. A tall, peaked T wave is the opposite finding and indicates hyperkalemia.

Visual 1: ECG strip comparison: A side-by-side view of a normal ECG, an ECG showing signs of hypokalemia (flat T wave, U wave), and an ECG showing hyperkalemia (tall, peaked T wave). This visual helps to contrast the ECG findings for opposite potassium imbalances.

Clinical Relevance

Nursing practice connection: Use the key finding related to ECG Interpretation in Electrolyte Imbalances to guide bedside assessment, documentation, and the next nursing action.
Continuous ECG monitoring is a critical nursing responsibility during IV potassium administration to detect hyperkalemia early and prevent cardiac arrest.
Never administer IV potassium as a push or bolus. It must always be diluted and infused slowly via an infusion pump to prevent fatal arrhythmias.
What if? If the patient also had chronic kidney disease, the risk of hyperkalemia from the infusion would be significantly higher. The nurse would need to advocate for a slower infusion rate, more frequent lab monitoring (serum potassium levels), and meticulously track urine output, as the kidneys are the primary route of potassium excretion.

How to Approach the Question

First, identify the core of the question: It asks for an ECG sign that would require the nurse to stop a potassium infusion.
Next, understand the purpose of the therapy. A potassium infusion is given to correct low potassium (hypokalemia).
Deduce the reason for stopping the therapy. The infusion would be stopped if the patient's potassium level becomes too high (hyperkalemia) due to over-correction.
Therefore, the question is asking for an ECG sign of hyperkalemia.
Evaluate the options by recalling the ECG manifestations of potassium imbalances. A tall, peaked T wave is the classic, earliest sign of hyperkalemia. The other options (prominent U wave, ST depression, shallow T wave) are all signs of hypokalemia.

Concept Tested & Keywords

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