# Situation: A 55-year-old woman has jaundice, itching, dark urine, and pale stools from a common bile duct stone that could not be removed endoscopically. She is scheduled for open cholecystectomy with common bile duct exploration. Her international normalized ratio (INR) is 1.8 (normal 0.8–1.2), and vitamin K is ordered before surgery. Which explanation of her prolonged INR is accurate?

> source: MyMerci (mymerci.kr)  
> url: https://mymerci.kr/pages/nclex_q.php?qn_id=630492  
> language: ko  
> subject: Nursing Practice IV — Care of Clients with Problems in Nutrition and Gastrointestinal, Metabolism and Endocrine, Perception and Coordination

## 문제

Situation: A 55-year-old woman has jaundice, itching, dark urine, and pale stools from a common bile duct stone that could not be removed endoscopically. She is scheduled for open cholecystectomy with common bile duct exploration.

Her international normalized ratio (INR) is 1.8 (normal 0.8–1.2), and vitamin K is ordered before surgery. Which explanation of her prolonged INR is accurate?

## 보기

1. Bilirubin in the blood blocks the clotting factors
2. Her liver cells have lost the ability to make clotting proteins
3. Without bile, the gut cannot absorb vitamin K well **✔ 정답**
4. Her platelets are trapped in an enlarged spleen

**정답: 3**

## 해설

Bile is needed to absorb fat and fat-soluble vitamins, including vitamin K, which the liver uses to make clotting factors II, VII, IX, and X. When bile cannot reach the intestine, vitamin K deficiency prolongs the INR, and parenteral vitamin K corrects it as long as the liver can still make these factors.

## 심화 해설

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.

## 임상 시나리오

Prolonged INR in Biliary ObstructionWhy vitamin K is ordered before surgery
Bile is needed to absorb fat-soluble vitamin K. When bile cannot reach the intestine, the liver cannot activate clotting factors II, VII, IX, and X, and the INR rises to 1.8.

Parenteral vitamin K corrects the INR as long as the liver can still make these factors; oral absorption is unreliable while the duct is blocked.

Monitor the INR after the dose and observe for bleeding.

CautionFailure of the INR to improve after vitamin K suggests liver synthetic failure and should be reported.

## 핵심 개념

- **International normalized ratio** — A standardized measure of prothrombin time used to assess clotting factor activity.
- **Vitamin K** — A fat-soluble vitamin required by the liver to activate clotting factors II, VII, IX, and X.
- **Fat-soluble vitamins** — Vitamins A, D, E, and K, which need bile and dietary fat for intestinal absorption.
- **Clotting factors** — Plasma proteins, mostly made in the liver, that interact to form a blood clot.

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