NCLEX-PN® ExaminationPhysiological AdaptationEasy
A client with a history of chronic kidney disease (CKD) is admitted with lethargy, muscle weakness, and peaked T-waves on the electrocardiogram. The nurse anticipates that the client's serum potassium level is likely:
- A5.0 mEq/L
- B6.5 mEq/L
- C2.5 mEq/L
- D3.8 mEq/L
Show answer & explanationAnswer & explanation
Correct answer: B. 6.5 mEq/L
Lethargy, muscle weakness, and peaked T-waves on an ECG are classic signs of hyperkalemia. In clients with CKD, the kidneys' inability to excrete potassium leads to elevated serum levels. A potassium level of 6.5 mEq/L is significantly elevated and consistent with these symptoms.
Why the other options are wrong
- A. 5.0 mEq/L is at the upper limit of normal; while it could be concerning for a CKD client, it is less likely to cause such pronounced symptoms and ECG changes as 6.5 mEq/L.
- C. 2.5 mEq/L indicates hypokalemia, which would present with different symptoms like muscle cramps, flattened T-waves, and U waves.
- D. 3.8 mEq/L is within the normal range (3.5-5.0 mEq/L) and would not typically cause these symptoms.
Hyperkalemia Symptoms & ECG
Hyperkalemia is an electrolyte imbalance characterized by elevated serum potassium levels (>5.0 mEq/L), often presenting with muscle weakness, fatigue, and distinctive ECG changes.
- Normal potassium range: 3.5-5.0 mEq/L.
- Common causes include kidney failure, certain medications, and acidosis.
- ECG changes progress from peaked T-waves to PR prolongation, QRS widening, and eventually asystole.
Memory trick: Too much Potassium, Heart and Muscles groan in exhaustion!