In what condition would you expect to see a prolonged PT/INR?

A prolonged PT/INR indicates an issue with the clotting factors that are dependent on vitamin K for their synthesis, specifically factors II, VII, IX, and X. Vitamin K plays a crucial role in the production of these clotting factors in the liver. When there is a deficiency in vitamin K, either due to inadequate dietary intake, malabsorption disorders, or other factors affecting vitamin K metabolism, the liver cannot produce these clotting factors effectively. This results in a prolonged PT/INR, as the blood takes longer to clot.

In the context of liver cirrhosis, although this condition can also lead to coagulopathy and a prolonged PT/INR due to impaired synthesis of clotting factors, the specific mechanism primarily involves the liver's ability to process and utilize vitamin K rather than a direct deficiency.

Dehydration usually causes hemoconcentration and can potentially alter other laboratory values, but it does not directly affect the PT/INR in the same way that vitamin K deficiency does. Anemia itself is a condition related to red blood cell count and does not directly influence the PT/INR levels unless there is related bleeding or significant blood loss.

Therefore, vitamin K deficiency is the most directly linked condition