A nurse is caring for a client who is receiving heparin by continuous IV infusion for treatment of venous thrombosis. Which of the following laboratory values should the nurse monitor for in order to titrate the heparin dose?

When caring for a client receiving heparin by continuous IV infusion for the treatment of venous thrombosis, the nurse should monitor the client's aPTT (Activated Partial Thromboplastin Time) to titrate the heparin dose.

Heparin is an anticoagulant medication used to prevent and treat blood clots. The aPTT is a coagulation test that measures the time it takes for the blood to clot when a specific activator is added. Monitoring the aPTT is a standard method for assessing the anticoagulant effect of heparin and ensuring that the client's blood remains within the desired therapeutic range.

The therapeutic range for aPTT while on heparin therapy varies depending on the indication and the client's condition but is generally maintained at a level that prolongs the clotting time enough to prevent and treat thrombosis while avoiding excessive bleeding risk.

Let's go through the other options:

A. Platelet function assay: While monitoring platelet function is essential for assessing overall hemostasis and platelet function, it is not specifically used for titrating heparin doses. Platelet function assays are more commonly used to assess the function of platelets in the context of platelet disorders or antiplatelet medication therapy.

C. INR (International Normalized Ratio): The INR is used to monitor the effect of vitamin K antagonist anticoagulants, such as warfarin, and is not the appropriate test for monitoring heparin therapy.

D. Amylase: Amylase is an enzyme produced by the pancreas and salivary glands and is not relevant for monitoring heparin therapy. Elevated amylase levels are typically associated with pancreatitis and not related to heparin treatment.

Furosemide is a loop diuretic commonly used to treat fluid volume excess by promoting diuresis. One of the expected outcomes of furosemide administration is an increased urinary output as excess fluid is eliminated from the body. Therefore, if the medication has been effective, the nurse would expect to see an increased urinary output as a result of the diuretic effect.

Increased respiratory rate (B) is not an expected outcome of furosemide administration. It may occur in some cases due to increased fluid elimination and potential electrolyte imbalances, but it is not the primary indicator of the medication's effectiveness.

Decreased blood pressure (C) is a possible outcome of furosemide administration due to the diuretic effect and subsequent reduction in fluid volume. However, it is not the most specific indicator of the medication's effectiveness in this case.

Increased pulse (D) is not a typical finding associated with the effectiveness of furosemide. In fact, furosemide can sometimes cause a decrease in heart rate due to its impact on fluid and electrolyte balance.