A client in the emergency department is admitted with a diagnosis of rule out myocardial infarction (MI). Which laboratory test should the nurse monitor to determine if the client has had an MI?

Question

A client in the emergency department is admitted with a diagnosis of rule out myocardial infarction (MI).  Which laboratory test should the nurse monitor to determine if the client has had an MI?

Quizplus · Accepted Answer

Troponin is a cardiac specific serum marker that is a highly specific indicator of MI and has greater sensitivity and specificity for myocardial injury than creatine kinase (CK) or CK-MB. Serum levels of troponin T and I increase 4-6 hours after the onset of MI, peak at 10-24 hours, and return to baseline in 10-14 days. However, MI is not diagnosed alone by serum cardiac markers. Electrocardiogram findings and client health history along with a history of pain and risk factors are also used to make the diagnosis of MI. (Option A) D-dimer is a laboratory test that measures the amount of cross-linked fibrin fragments resulting from clot degradation. It is ordered for clients with suspected pulmonary embolism. (Option B) LDL is used in determining cardiac disease risk, not for diagnosing MI. (Option C) Myoglobin is released into the circulation within 2 hours after MI. Although it may be the first serum cardiac marker to appear after MI, it lacks cardiac specificity and its role in diagnosing MI is limited. Educational objective: The nurse should monitor serum troponin levels when there is suspicion of MI as it is the most sensitive and specific serum cardiac marker.

A Client in the Emergency Department Is Admitted with a Diagnosis