NCLEX Answer: Potassium 2.8
The question: A patient's lab results show a potassium level of 2.8 mEq/L. Which finding should the nurse expect?
A) Hyperreflexia
B) Positive Trousseau's sign
C) U waves on the ECG
D) Prolonged bleeding time
✅ The answer is C) U waves on the ECG
A potassium level of 2.8 mEq/L is low. Normal is 3.5 to 5.0 mEq/L, so this patient has hypokalemia, and U waves on the ECG are a classic sign of it.
How to decode it with my S.M.A.R.T. framework
- Scan for the clue: potassium of 2.8 mEq/L.
- Match it to context: low potassium means hypokalemia, and potassium imbalances show up on the ECG.
- Analyze the opposites: hyperreflexia goes with high potassium, the opposite of what is happening here.
- Rule out distractors: a positive Trousseau's sign points to low calcium, and prolonged bleeding time points to a clotting problem. Neither is about potassium.
- Target the best answer: C) U waves on the ECG.
Notice you didn't need to memorize every lab value. You needed to spot the clue, then know what to do with it. That's content plus strategy, and you need both to pass the NCLEX.
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