The nurse practitioner is reviewing laboratory results for a 65-year-old man with a history of diabetes mellitus and heart failure. His most recent potassium (K⁺) level is 5.5 mEq/L. Which of the following is the next appropriate step?

Do nothing; this is an expected finding.

Call this patient and have him go to the local hospital to be admitted.

Have him come into the office for intravenous (IV) fluids, then recheck his potassium level.

Have him come into the office for an electrocardiogram, then decide whether he needs to be admitted.