Platelet count is not the primary diagnostic test used to monitor the therapy’s effect of warfarin. Platelets are involved in the clotting process, but warfarin specifically works by inhibiting the synthesis of vitamin K-dependent clotting factors, which does not directly involve platelets.

Choice B rationale

The white blood cell count (WBC) is not used to monitor the effect of warfarin therapy. WBC is typically used to monitor for infection or inflammation, not the coagulation status of a patient.

Choice C rationale

Prothrombin time (PT) is the correct answer. Warfarin therapy is monitored using the PT, which is reported as the International Normalized Ratio (INR). Warfarin inhibits the synthesis of vitamin K-dependent clotting factors, which include Factors II, VII, IX, and X, and Proteins C and S. The PT/INR is sensitive to changes in these factors. An elevated INR indicates a higher risk of bleeding, while a lower INR suggests a higher risk of clotting.

Choice D rationale

Activated partial thromboplastin time (aPTT) is not typically used to monitor warfarin therapy. The aPTT test evaluates the intrinsic and common pathways of coagulation, which includes factors XII, XI, IX, VIII, X, V, II (prothrombin), and I (fibrinogen). Warfarin affects the extrinsic pathway and common pathway, not the intrinsic pathway. Therefore, aPTT is not the best test to monitor the effects of warfarin.

Choice A rationale

Changing gloves between tasks on the same client is a key infection control practice. This prevents cross-contamination between different body sites and reduces the risk of spreading infection.

Choice B rationale

Washing hands with alcohol-based hand rubs when caring for a client who has Clostridium difficile is not recommended. Clostridium difficile spores are not killed by alcohol-based hand rubs. Handwashing with soap and water is more effective.

Choice C rationale

Using alcohol-based hand rubs before administering eye drops for a client is a good practice, but it is not the most important information to reinforce. Hand hygiene is crucial in all aspects of patient care to prevent the spread of infection.

Choice D rationale

Keeping artificial nails trimmed short is a good practice, but it is not the most important information to reinforce. Artificial nails can harbor bacteria and other pathogens, increasing the risk of infection transmission.