A patient was brought to the emergency department and a blood sample was sent for serum electrolyte level. The report shows that the serum potassium level is 6.5 mmol/L. So, the interpretation is:

1. A

   It is within the reference range

2. B

   It is higher than normal

3. C

   It is below normal

4. D

   It is within the normal level

Appeared in: DSSSB 13 August 2024

Explanation

• The normal serum potassium concentration ranges from 3.5 to 5.0 mmol/L (or mEq/L).
• A reported value of 6.5 mmol/L is significantly higher than the upper limit of the normal range.
• This condition of elevated serum potassium is termed hyperkalemia.
• A serum level exceeding 5.5 mEq/L is considered toxic and dangerous, necessitating immediate reporting and intervention.

Why Other Options Were Wrong

• Option A: This is incorrect. The value 6.5 mmol/L is well above the normal reference range of 3.5-5.0 mmol/L.
• Option C: This is incorrect. A level of 6.5 mmol/L is higher, not lower, than the normal range. A level below 3.5 mmol/L would be considered below normal (hypokalemia).
• Option D: This is synonymous with 'within the reference range' and is incorrect for the same reason. 6.5 mmol/L is not a normal potassium level.

Related Visual

Clinical Relevance

• Nursing practice connection: Prioritize focused assessment, early escalation, and real-time monitoring when managing Interpretation of serum potassium levels in acute care settings.
• Hyperkalemia is a medical emergency because it can lead to life-threatening cardiac dysrhythmias, such as ventricular fibrillation or asystole, and cardiac arrest.
• A nurse's primary responsibilities for a patient with hyperkalemia include continuous cardiac monitoring (ECG), notifying the physician immediately, and preparing to administer emergency medications like calcium gluconate, insulin with dextrose, or sodium polystyrene sulfonate (Kayexalate).
• What if? If the patient's potassium level was 2.5 mmol/L, the interpretation would be 'It is below normal,' indicating hypokalemia. This is also a serious condition requiring potassium replacement and cardiac monitoring for different types of arrhythmias.

How to Approach the Question

• First, identify the key information provided in the question: the laboratory value is a serum potassium of 6.5 mmol/L.
• Next, recall the standard normal reference range for serum potassium, which is 3.5 to 5.0 mmol/L.
• Compare the patient's value (6.5 mmol/L) to the normal range.
• Determine if the patient's value is below, within, or above the normal range.
• Since 6.5 is greater than 5.0, the level is higher than normal.
• Select the option that accurately reflects this finding.

Concept Tested & Keywords

• Concept Tested: Interpretation of serum potassium levels
• Stem keywords: serum electrolyte level, serum potassium, 6.5 mmol/L
• Lead-in keywords: interpretation
• Clinical cues: A serum potassium level of 6.5 mmol/L is a critical value requiring immediate action.

Question ID

QZIb8Alo86TUGEQ7i0qb2i

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Reference Book

E6 Pharmacology Nursing Lilley 11e Part 2 p. 168-170

E6 Nursing Brunner Adult Health 3SA Vol 1 Part 1 p. 149-151