The nurse is caring for a client who is taking digoxin and is complaining of nausea. The nurse gathers additional assessment data and checks the most recent laboratory results. Which laboratory value requires the need for follow-up by the nurse?

1. A

   Sodium 138 mEq/L

2. B

   Potassium 3.3 mEq/L

3. C

   Phosphorus 3.1 mg/dl

4. D

   Magnesium 1.8 mg/dl

Appeared in: JIPMER Pondicherry NO - 2022

Explanation

• The client's potassium level of 3.3 mEq/L is below the normal range of 3.5-5.0 mEq/L, indicating hypokalemia.
• Hypokalemia is a critical risk factor for digoxin toxicity because low potassium levels increase the binding of digoxin to the Na+/K+ ATPase pump in cardiac cells, enhancing the drug's effect.
• The client's symptom of nausea is a classic early sign of digoxin toxicity, making the low potassium level the most urgent finding to address.

Why Other Options Were Wrong

• Option A: A sodium level of 138 mEq/L is within the normal range of 135-145 mEq/L and does not require immediate follow-up.
• Option C: A phosphorus level of 3.1 mg/dL is within the normal range of 2.5-4.5 mg/dL and is not directly associated with an increased risk of digoxin toxicity.
• Option D: A magnesium level of 1.8 mg/dL is within the normal range of 1.6-2.6 mg/dL.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Digoxin toxicity and its relationship with electrolyte imbalances to guide bedside assessment, documentation, and the next nursing action.
• Nurses must always verify potassium levels before administering digoxin, especially for clients on potassium-wasting diuretics (e.g., furosemide), as this combination significantly increases toxicity risk.
• It is a critical nursing responsibility to educate patients on the signs of toxicity (like nausea, vision changes) and the importance of regular lab monitoring.
• What if? If the client's potassium was normal (e.g., 4.1 mEq/L) but their creatinine was high (e.g., 2.5 mg/dL), the priority would be the elevated creatinine. This indicates impaired renal function, which is the most common cause of digoxin accumulation and toxicity.

How to Approach the Question

• First, identify the key information in the stem: the client is taking digoxin and experiencing nausea.
• Recognize that nausea is a common early symptom of digoxin toxicity.
• The question asks to identify the lab value that requires follow-up, implying one of the values is abnormal and linked to the clinical picture.
• Recall the major electrolyte imbalances that potentiate digoxin toxicity. The most well-known is hypokalemia (low potassium).
• Systematically evaluate each option against its normal range: Sodium 138 (Normal), Potassium 3.3 (Low), Phosphorus 3.1 (Normal), Magnesium 1.8 (Normal).
• Conclude that the low potassium level (hypokalemia) is the most significant finding, as it directly explains the increased risk for the client's symptoms of digoxin toxicity.

Concept Tested & Keywords

• Concept Tested: Digoxin toxicity and its relationship with electrolyte imbalances.
• Stem keywords: digoxin, nausea, laboratory results, follow-up
• Lead-in keywords: requires the need for follow-up
• Clinical cues: Client taking digoxin: This immediately signals the need to monitor for toxicity.
• Clinical cues: Client complaining of nausea: This is a classic early sign of digoxin toxicity.

Question ID

Q2pM5wNxM0H_Z6fHMtbACQ

Copy ID

Reference Book

E6 Pharmacology Nursing Lilley 11e Part 2 pp. 73-75, 156-158

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 1 p. 156-158