Canadian Practical Nurse Registration Examination (CPNRE) 2026 – 400 Free Practice Questions to Pass the Exam

The correct choice involves checking the Partial Thromboplastin Time (PTT) and activated Partial Thromboplastin Time (aPTT) before administering Heparin. This is essential because Heparin is an anticoagulant that enhances the effect of antithrombin III and prolongs the clotting time by inhibiting thrombin and factor Xa in the coagulation cascade.

Monitoring PTT and aPTT allows healthcare professionals to ensure that the patient is within the therapeutic range for Heparin, thus minimizing the risk of bleeding complications as well as validating the effectiveness of the medication being administered. This is particularly important given the narrow therapeutic index of Heparin.

While other laboratory tests such as PT and INR are crucial for monitoring patients on warfarin and assessing the extrinsic pathway of coagulation, they do not provide relevant information for Heparin therapy. Hemoglobin (Hgb) and hematocrit (Hct) levels can indicate changes in oxygen-carrying capacity and overall blood volume but are not specific to coagulation status. BUN (Blood Urea Nitrogen) and creatinine levels are important for assessing kidney function but also do not directly relate to the action of Heparin or its monitoring.