Final answer:
The nurse monitors partial thromboplastin time (PTT) during hemodialysis in order to assess the therapeutic effectiveness and safety of heparin anticoagulation. PTT is chosen as it reflects the activity of clotting factors in the intrinsic and common pathways, which are influenced by heparin. Other tests like PT, TT, and bleeding time are not typically used to monitor heparin therapy in this context.
Step-by-step explanation:
During hemodialysis, administration of an anticoagulant such as heparin is essential to prevent clotting within the dialysis circuit. To monitor the effectiveness and safety of heparin therapy, nurses in a clinical setting typically measure the partial thromboplastin time (PTT). This test evaluates the function of various factors involved in the intrinsic and common pathways of the coagulation cascade, which are influenced by heparin. Regular monitoring of PTT during hemodialysis ensures that the anticoagulation effect is within the desired therapeutic range without increasing the risk of bleeding.
Other tests such as prothrombin time (PT), thrombin time (TT), and bleeding time also assess clotting function but serve different purposes or are impacted by different factors. PT assesses the extrinsic pathway and is not directly affected by heparin therapy, therefore, it is not typically used to monitor heparin therapy during dialysis. TT is more sensitive to the effects of heparin than PTT but is less commonly used in this clinical context. Bleeding time is a measure of platelet function and vascular integrity rather than coagulation factor activity, thus it is not used to monitor heparin therapy.