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. Common mechanisms of liver insufficiency

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.);