Question

The nurse is monitoring a client who is attached to a cardiac monitor and notes the presence of U waves. The nurse assesses the client and checks his or her most recent electrolyte results. The nurse expects to note which electrolyte value?

a) Sodium 135 mEq/L
b) Sodium 140 mEq/L
c) Potassium 3.0 mEq/L
d) Potassium 5.0 mEq/L

Answer 1

The nurse would expect to see a potassium value lower than the normal range (3.5 to 5.0 mEq/L) due to the presence of U waves on the cardiac monitor, indicating hypokalemia, not a value of 5.0 mEq/L as mentioned in the question.

Step-by-step explanation:

When a nurse observes the presence of U waves on a cardiac monitor, one potential cause might be an abnormal electrolyte balance, specifically low potassium levels in the blood, a condition known as hypokalemia. Reference values for potassium in blood plasma indicate that a normal level is usually between 3.5 to 5.0 mEq/L.

The presence of U waves is more often associated with hypokalemia (potassium levels lower than the normal range), rather than hyperkalemia, which is characterized by elevated potassium levels and might lead to more severe symptoms such as muscle weakness, paralysis, or cardiac disturbances. Given the connection between low potassium levels and the appearance of U waves, upon reviewing electrolyte results, the nurse would anticipate a potassium value that is lower than 3.5 mEq/L, not 5.0 mEq/L as stated in the question. Therefore, the expected electrolyte value should reflect hypokalemia, not a normal or elevated potassium level.