Vitamin K needs bile to be absorbed
Bile salts are essential for forming micelles that allow dietary fat and the fat-soluble vitamins A, D, E, and K to be absorbed from the small intestine. When a common bile duct stone stops bile from reaching the duodenum, fat absorption falls and vitamin K deficiency develops. The liver needs vitamin K to produce functional clotting factors II, VII, IX, and X. Without it, these factors are made in inactive form, and the international normalized ratio (INR) rises. Her INR of 1.8 reflects poor vitamin K absorption caused by biliary obstruction.
Why vitamin K corrects it
Because her liver cells are still able to synthesize clotting proteins, giving parenteral vitamin K bypasses the gut problem and allows the liver to activate the factors again. The INR usually improves within a day or so, which reduces bleeding risk before surgery. The route matters: oral vitamin K depends on bile for absorption, so it is less reliable while the duct is blocked. The nurse monitors the INR after the dose and observes for bleeding from puncture sites, gums, or the urine.
| Cause of prolonged INR | Responds to vitamin K? | Fits her? |
|---|
| Biliary obstruction, poor vitamin K absorption | Yes | Yes |
| Advanced cirrhosis, loss of synthetic function | Little or no response | No |
| Bilirubin inactivating factors | Not a real mechanism | No |
| Platelets trapped in the spleen | Affects platelet count, not INR | No |
Why the other explanations are wrong
Bilirubin does not inactivate clotting factors; high bilirubin and prolonged INR share a cause but are not linked directly. Loss of hepatic synthetic function occurs in advanced cirrhosis and would not be corrected by vitamin K, because the liver cannot make the proteins at all. Splenic sequestration lowers the platelet count, which prolongs bleeding time but does not change the INR, a measure of clotting factor activity. Watch out! The response to vitamin K is the clue that separates obstruction from liver failure.
Exam takeaway
Clients with obstructive jaundice need their coagulation status checked before surgery or invasive procedures. Key point! Bile is required to absorb vitamin K; when bile cannot reach the gut, the INR rises and parenteral vitamin K corrects it if the liver is still working.