Editing Medical-Surgical Nursing – RN Practice Questions (section)

==Question 2==
A patient presents to the emergency department with substernal chest pain that began three hours ago. The initial troponin is within normal limits. What is the nurse's best interpretation of this result?
# The pain is not cardiac in origin, so cardiac monitoring can be discontinued.
# Myocardial infarction is ruled out and the patient can be discharged.
# Troponin may not yet be elevated this early, so serial levels and continued monitoring are required.
# The troponin result is invalid and the specimen should be redrawn immediately.

'''Answer:''' Option 3, troponin may not yet be elevated this early, so serial levels and continued monitoring are required.

''Rationale:'' Troponin begins to rise roughly three to four hours after myocardial injury, peaks around twelve to twenty-four hours, and remains elevated for up to ten to fourteen days. A single early normal value does not exclude infarction, so serial troponins, serial electrocardiograms, and continuous rhythm monitoring continue. Options 1 and 2 are unsafe because they act on an incomplete data set. Option 4 assumes laboratory error without evidence.