Progressive Care Nursing Certification (PCCN) Practice Exam

Which factor must be present in adequate levels for effective clot formation?

1. Vitamin K

2. Calcium

3. Factor V

4. Factor VII

The correct answer is: Calcium

Calcium plays a critical role in the clotting process as it is an essential cofactor in several steps of the coagulation cascade. It is required for the activation of certain clotting factors, specifically those in the intrinsic and extrinsic pathways of hemostasis. Calcium facilitates the binding of clotting factors to phospholipid surfaces that are exposed by activated platelets, thereby promoting the conversion of prothrombin to thrombin and the subsequent conversion of fibrinogen to fibrin, the protein that forms the meshwork structure of a blood clot. Without adequate levels of calcium, the entire clotting process would be impaired, leading to deficits in effective hemostasis and increased risk for bleeding complications. This is why maintaining appropriate calcium levels is crucial for the formation of stable and effective blood clots in the body. Other factors listed, such as Vitamin K, Factor V, and Factor VII, while important for clotting, are not directly responsible for the essential role calcium plays in activating and facilitating the interactions necessary for clot formation. Therefore, the necessity of calcium for effective clot formation is paramount.