A nurse is caring for a client who is scheduled for a bone marrow aspiration. The client asks the nurse about the sites the provider might use for the procedure. Which of the following locations should the nurse identify as one of the sites used for this procedure?

A. This result indicates muscle injury but does not specify the source.

This statement is partly correct. An elevated troponin I level does indicate muscle injury, specifically damage to the heart muscle. However, troponin I is highly specific to cardiac muscle, so an elevated level would indeed specify the source as cardiac or myocardial injury.

B. Because the client has a history of unstable angina, this is a poor indicator of myocardial injury.

This statement is incorrect. A history of unstable angina does not diminish the significance of an elevated troponin I level. In fact, unstable angina is itself a serious condition that can lead to myocardial injury or heart attack, and an elevated troponin I level in this context indicates ongoing or recent myocardial damage.

C. This is only an accurate indicator of myocardial damage when it reaches its peak in 24 hours.

This statement is not entirely accurate. While it is true that troponin I levels may continue to rise and peak within 12-24 hours after the onset of myocardial injury, an elevated troponin I level at any point is still a significant indicator of myocardial damage. It's essential to recognize elevated troponin I levels promptly to initiate appropriate interventions and monitor the client's cardiac status closely.

D. This is an accurate indicator of myocardial injury.

This statement is correct. An elevated troponin I level is a highly sensitive and specific marker of myocardial injury. It indicates damage to the heart muscle, which can occur due to conditions like unstable angina, heart attack (myocardial infarction), myocarditis, or other cardiac issues. Therefore, recognizing an elevated troponin I level in a client with unstable angina is crucial for proper management and further evaluation.

To calculate the volume of heparin to administer subcutaneously, you can use the following formula:

Volume (mL) = Desired dose (units) / Concentration (units/mL)

In this case:

Desired dose = 3,800 units

Concentration = 5,000 units/mL

Volume (mL) = 3,800 units / 5,000 units/mL ≈ 0.76 mL

Rounded to the nearest tenth, the nurse should administer approximately 0.8 mL of heparin subcutaneously daily.