Question

The client with a joint replacement is scheduled to receive Lovenox (enoxaparin). Which lab value should be reported to the doctor? A. PT of 20 seconds B. PTT of 300 seconds C. Protime of 30 seconds D. INR 3

Short answer

Answer: The most important lab value to report for a patient scheduled to receive Lovenox is their PTT (Partial Thromboplastin Time) because it measures the time it takes for a blood clot to form and assesses the intrinsic pathway of the coagulation cascade. This value indicates the effect of Lovenox on blood clotting and helps the doctor to monitor the patient's risk of bleeding or adjust their Lovenox dosage accordingly.

Step-by-step solution

Understanding Lovenox

Lovenox (enoxaparin) is an anticoagulant, which means it prevents blood clots from forming. It works by inhibiting the formation of fibrin, which is necessary for blood clotting. This medication is often prescribed to patients after joint replacement surgery to reduce the risk of developing deep vein thrombosis (DVT) or other blood clots.

Explaining the Lab Tests

A. PT (Prothrombin Time): This measures the time it takes for a clot to form in a blood sample. It assesses the extrinsic pathway of the coagulation cascade. An increased PT means that it takes longer for blood to clot, which could indicate the effectiveness of an anticoagulant. B. PTT (Partial Thromboplastin Time): This test measures the time it takes for a blood clot to form in a blood sample, assessing the intrinsic pathway of the coagulation cascade. Similar to PT, an increased PTT implies that it takes longer for the blood to clot. C. Protime: This is another term for PT. D. INR (International Normalized Ratio): This is a standardized way of expressing PT results, which allows for consistency across different laboratories. A higher INR indicates that it takes longer for the blood to clot. An INR around 2-3 is typically the target range for patients on anticoagulant therapy.

Determining the Most Important Lab Value to Report

Given that Lovenox (enoxaparin) is an anticoagulant, we need to report the lab value that demonstrates its effect on blood clotting. In this case, since enoxaparin has a more significant effect on the intrinsic pathway of the coagulation cascade, PTT (B) would be the most important lab value to report. PTT of 300 seconds is significantly prolonged and should be reported to the doctor, as it may indicate an increased risk of bleeding or require an adjustment to the patient's Lovenox dosage.