26. TYPICAL FORMS OF PATHOLOGY OF THE LIVER. JAUNDICE

Metabolic processes in which the liver plays a major role are the following:

• intermediate metabolism of amino acids and carbohydrates;

• synthesis and degradation of proteins and glycoproteins;

• metabolism and degradation of drugs and hormones;

• regulation of lipid and cholesterol metabolism. Etiology of the liver damage:

• Damage to the liver parenchyma or bile ducts:

- hepatitis (viral, bacterial, toxic);

- dystrophy;

- cirrhosis;

- tumors;

- parasites;

- gall bladder stones, inflammation of the bile ducts with cholestasis.

• Extrahepatic causes:

- shock;

- heart failure;

- general hypoxia;

- renal failure;

- protein malnutrition;

- metastases in the liver.

LIVER FAILURE

Liver failure is characterized by a decrease of one or many functions below the level required to maintain normal homeostasis. It can be classified by the number of deranged functions as partial and total; by the clinical course as acute and chronic; and by the outcome as lethal and nonlethal. The common mechanisms operating in liver failure are described in fig. 35.

Fig. 35

Manifestations of liver failure:

• Carbohydrate metabolism:

- hyperglycemia, glucose intolerance;

- increased blood lactate levels;

- hypoglycemia.

• Amino acid and ammonia metabolism:

- elevated levels of aromatic amino acids and methionine;

- normal or depressed levels of the branched-chain amino acids;

- increased levels of free amino acids;

- a reduction in blood urea nitrogen;

- an accumulation of ammonia in the blood.

• Protein synthesis and degradation:

- hypoprothrombinemia;

- hypoalbuminemia;

- a decreased plasma concentration of factor V;

- an increased production of fibrinogen (possibly abnormal) and other acute-phase reactants (C-reactive proteins, haptoglobin, etc.);