Types of Jaundice and Its Treatment

Also known as icterus, jaundice is also characterized by a yellow discoloration of the skin, the whites of the eyes (sclera) and other tissues as a result of excessive levels of bilirubin in the blood and tissue fluids.

Other causes of skin yellowing such as excessive levels of carotene in the blood are distinguishable from jaundice because the sclera is generally unaffected.

Red blood cells (erythrocytes) have a life span of about 120 days. Old and damaged erythrocytes are broken down by the reticulo-endothelial system, particularly in the liver, spleen and bone marrow. Bilirubin is formed from the breakdown of the hemoglobin from the destroyed erythrocytes, and is released into the circulating blood. As the blood passes through the liver, liver cells remove the bilirubin, conjugate it ( add to it a salt so that it becomes water soluble and able to be excreted), and release it in the bile. The bile duct takes this fluid via the gall bladder to the small intestine, where it assists in the absorption of fats and is then excreted in the feces.

Bilirubin gives the bile its characteristic yellow-green hue, and after being converted to stercobilinogen and stercobilin by bacteria in the small bowel, gives the feces their brown color.

The normal blood level of bilirubin is 5 to 17 mmol per liter. Jaundice is usually not apparent until the level has reached 35 mmol per liter.

There are three major causes of jaundice: excessive breakdown of red blood cells (hemolytic jaundice), damage to the cells in the liver (hepatocellular jaundice), and obstruction of the bile ducts (obstructive jaundice).

Hemolytic jaundice

In this form, overproduction of bilirubin results from excessive breakdown of red blood cells (hemolysis). For this process to cause jaundice, the degree of hemolysis usually has to be severe enough to produce a degree of anemia as well.

Causes are many and include defects in the structure of the hemoglobin (thalassemia), faulty red blood cell membranes (spherocytosis) and infection in the blood cells (malaria). Each of these make the red blood cells more fragile and susceptible to hemolysis. Normal red cells may also occasionally be ‘attacked’ by abnormal antibodies; this may be triggered by drugs, by incompatible blood transfusions, or be part of Rhesus disease of the newborn.

Hepatocellular jaundice

Damaged liver cells cannot remove and conjugate the normal quantity of bilirubin circulating in the blood, thus causing the level of bilirubin in the blood to rise. Viral hepatitis is the most common liver disease that causes jaundice. Liver inflammation caused by certain toxic chemicals, alcohol (alcoholic hepatitis), and glandular fever may also be associated with jaundice.

Obstructive jaundice

When the bile duct is blocked, bilirubin builds up in the liver. As it no longer being excreted from the body the level in the bloodstream then rises and produces jaundice. The most common cause of obstructive jaundice is a gallstone leaving the gall bladder and becoming lodged in the bile duct. In older people, cancers of the gall bladder and pancreas may also obstruct the duct. Occasionally, hydatid cysts and liver tumors may become large enough to block off bile excretion before it leaves the liver.

Some drugs, particularly the phenothiazines and the sex hormones may occasionally produce obstruction by causing a ‘stasis’ of bile within the liver itself.

Diagnosis

The history, clinical findings and special blood tests usually enable the mechanism and specific cause of the jaundice to be identified. Hemolytic jaundice is associated with dark feces, anemia, a normal liver and abnormal blood films which show the increased destruction and turnover of red blood cells.

Diseases of the liver usually result in that organ becoming enlarged and tender to touch. Special liver function tests become abnormal and show elevated levels of certain enzymes in the presence of specific liver diseases.

Obstructive jaundice is associated with light colored feces and dark urine, as some bilirubin is excreted through the kidneys. The blood level of an enzyme, serum alkaline phosphatase, becomes elevated and the bilirubin level tends to be higher than in other forms of jaundice.

Treatment

The treatment of jaundice depends on the cause. Surgical relief of bile duct obstruction may be required.

Where the jaundice is the result of hepatic disease, the diet is important. Patients are generally prescribed a high protein, high carbohydrate, low fat, high energy diet, except where there is liver failure, when protein intake may have to be restricted. Drugs which are known to be inactivated by the liver (such as oral contraceptives) are best avoided as are potential hepatotoxic agents such as alcohol. Supplemental vitamins may be required.

Source:

HEPATO-GASTROENTEROLOGY

Volume: 16

Issue: 18

Pages: 393-397

Published: May 1998