89.56歲男性皮膚及鞏膜泛黃，且有茶色尿及灰白便。下列敘述何者正確？
(A)此病人有溶血性黃疸
(B)若摸到腫大的膽囊，病人肝外膽管阻塞
(C)血中升高的膽紅素主要是非接合型膽紅素
(D)肝癌細胞因為會製造過多膽紅素也特別容易出現此類黃疸

黃疸(jaundice)是由於Bilirubin代謝障礙而引起血中Bilirubin升高，導致皮膚、鞏膜、黏膜呈現黃色表徵。

89.

56歲男性皮膚及鞏膜泛黃，且有茶色尿及灰白便。下列敘述何者正確？

膽色素一部份會隨腸肝循環回收,另一部分則會經由糞便或尿液排出,使得糞便會有土黃的顏色。

若看到灰白便,則要想到兩個原因:

1.是肝臟製造膽色素不足(肝臟的問題);

2.是膽管阻塞致膽色素不能進入腸道。

又看到有茶色尿,代表肝臟製造之 direct/conjugated 膽色素無法從糞便排出,只能全部由尿液排出,而使尿液呈茶色。

(A)此病人有溶血性黃疸

(B)若摸到腫大的膽囊，病人肝外膽管阻塞

阻塞性黃疸：

根據阻塞的部位可分為肝外膽管阻塞及肝內膽管阻塞：

(1) 引起肝外膽管阻塞疾病，有膽總管結石、狹窄、蛔蟲堵塞，腫瘤壓迫膽道，以及先天性膽道閉鎖等。

(2) 肝內膽管阻塞常見於結石、癌栓、藥物(如Chlopromazine、testosterone所致)、PBC等。

 
(C)血中升高的膽紅素主要是非接合型膽紅素

肝臟製造的 direct/conjugated (接合型)膽色素無法從糞便排出

(D)肝癌細胞因為會製造過多膽紅素也特別容易出現此類黃疸 .

肝細胞性黃疸：

因肝細胞大面積的損害而引起黃疸，

如viral hepatitis、中毒性及藥物性肝炎、

原發性與繼發性 肝細胞癌、Leptospirosis、肝硬化等。

End product of phagocytosing an RBC: unconjugated bilirubin.  When the RBC is broken down, you have hemoglobin, and there is an enzyme that splits heme from globin and the globin is broken into aa’s and therefore goes to the aa pool. Then, takes the heme, splits it open, and saves the Fe. Now you have protoporphyrin, and spit it out; end result is unconjugated bilirubin in the macrophage within the spleen.  Then, the macrophage spits out the unconjugated bilirubin into blood stream (which is insoluble b/c it’s unconjugated).   The unconjugated bilirubin then binds albumin and goes to the liver and is conjugated.  So, what clinical finding will you see in pts with extravascular hemolytic anemia? Jaundice.  Does that bilirubin get into the urine? No. Why? 2 reasons:  (1) Lipid soluble and (2) Bound to albumin (albumin does not get into the urine) – so you are jaundiced, but doesn’t get into the urine

unconjugated bilirubin gets taken up by the liver and is conjugated.  Any time the cytochrome p450 conjugates bilirubin, or metabolizes any drug, it renders it water soluble.  So, we have a lipid soluble unconjugated bilirubin is converted to conjugated bilirubin (direct bilirubin), which is water soluble.  One of the purposes of the liver is to render lipid soluble drugs water soluble, so you can pee them out.  So, we conjugate it and have water soluble bilirubin.  Once bilirubin is taken up by the liver, it is never close to a vessel.  So, there is no way it can get into a vascular channel (once it is taken up by the liver).  So, if direct conjugated bilirubin is in our urine, this is b/c something happened (either in the liver or bile duct) to have caused it to get there b/c it shouldn’t have access to our blood stream.   So, it is taken up in the liver, conjugated, and pumped into the bile ductules; which go into the triad, goes up the common bile duct, some is stored in the GB and goes into the small intestine through the common bile duct.  Therefore, bile contains conjugated bilirubin.