A nurse is caring for a group of toddlers receiving digoxin therapy. For which of the following toddlers should the nurse revise the plan of care?

A toddler who has a digoxin level of 1.2 ng/mL (0.8 to 2 ng/mL).

A toddler who has an apical pulse of 100/min.

A toddler who has a potassium level of 4.0 mEq/L (3.4 to 4.7 mEq/L).

A toddler who has vomited 2 times in the last hour.