Bilirubin - what is it ?What is dangerous high bilirubin in the blood ?
Analyses And Studies / / August 12, 2017
- blood test for bilirubin
- Types bilirubin
- bilirubin bilirubin level in newborns
- Under what conditions bilirubin decreases?
- Why increases the concentration of bilirubin?
- What is dangerous high bilirubin?
blood test for bilirubin
bilirubin - a substance that is produced in the human body at the disposal of destroyed or damaged red blood cells.Initially, it is formed from parts of hemoglobin in spleen cells and then enters into the liver and is converted into water-soluble form.Bilirubin output in bile and generally in small quantities - urine.Blood analysis shows the total concentration of the substance, as well as its fractions.This study is very important, because at the critical raising the level of to
bilirubin bilirubin in the body presented in the form of several factions:
- Indirect faction, which bile pigments.It is insoluble in water and can penetrate the cell membrane.Related to this is the main toxic effect.This fraction of bilirubin is synthesized in cells of the reticuloendothelial system by enzymatic transformation of heme, which is formed by the breakdown of hemoglobin.Further, it binds to the carrier proteins, mostly albumin, and penetrates into the liver.Direct
- fraction (free) produced in liver cells by the compound with glucuronic acid.Through this reaction becomes soluble pigment properties together with bile enters the duodenum 12.In the gastrointestinal tract bilirubin undergoes further changes.A small portion of it back into the blood is absorbed and then filtered in the kidney and excreted in urine.The same basically it eventually turns into stercobilin contained in feces and provides its characteristic color.
Some patients do not fully understand what the total bilirubin in a blood test.This value is obtained by adding the concentration of direct and indirect fractions.
Standard blood chemistry is performed on an empty stomach, a liquid sample was taken from a vein (usually at the elbow).To obtain reliable results, prior to blood donation should be, at least knock, refuse to accept the fatty foods and alcohol.Also, the test results can be influenced by:
- some drugs acting on blood clotting (heparin, warfarin, aspirin);
- overeating or adherence to a strict diet, in particular, fasting;
- caffeinated beverages;
- cholagogue grass.
Typically, a blood test for bilirubin is carried out in the following situations:
- during the clinical examination;
- with the appearance of jaundice symptoms, including neonates;
- for the diagnosis of liver function in hepatitis, cirrhosis, tumors;
- the presence of gallstones or pancreatitis;
- hemolytic disease;
- at various kinds of poisoning and toxic effects;
- as monitoring the effectiveness of therapy.
in blood plasma is determined by three indicators:
- total bilirubin, which is the total concentration of water-soluble and fat-soluble fractions.Norma him in an adult is 5,1-17 mol / L.
- Indirect fraction can vary between 3,4-12 micromoles / liter.Its share is usually 70-75%.
- Direct fraction normally is 1,7-5,1 mmol / l.
When pregnancy is a slight increase in the concentration of the substance can be regarded as the norm.This is due to a violation of blood flow in the portal vein as a result of increased intra-abdominal pressure and the impact of enlarged uterus.
bilirubin levels in newborns
bilirubin concentration in plasma of newborns varies.This is due to the fact that after the start of the breath through the lungs changes the composition of the baby's blood.In particular, there is a substitution of a conventional fetal hemoglobin.Therefore there is a massive destruction of the substance and the formation of large amounts of heme and thus the bilirubin.Normal values considered:
- in children in the first hours after birth - less than 60 mmol / l;
- on the third or fourth day - no more than 250 mmol / l (in premature babies, the figure is 170 mmol / l);
- a week - less than 170 mmol / l.
Subsequently, the concentration of this substance in the blood of the child is gradually reduced to the level of an adult.
Under what conditions bilirubin decreases?
Low bilirubin rarely detected.Most often it is observed in the presence of ischemic heart damage.However, no specific indication is not used in the diagnosis of disease.The same situation may occur in patients receiving certain medications (phenobarbital, ascorbic acid, theophylline).
Another reason for such a change could be erroneous determination of the concentration.That is why in such cases it is desirable to perform follow-up study.
Why increases the concentration of bilirubin?
level of bilirubin in the blood can rise for three reasons:
- massive destruction of red blood cells (hemolysis);
- forming obstacles in the biliary tract;
- breach formation water-soluble fraction in the liver cells.
active destruction of red blood cells can be observed under the influence of intoxicating agents at the wrong blood transfusion, as well as a result of hemolytic diseases.Since there is an active removal of toxic substances from the body, usually the urine becomes dark.
Violation of hepatic bilirubin metabolism caused by the defeat of hepatocytes.This occurs when the following diseases:
- hepatitis virus or toxic etiology;
- liver cirrhosis;
- result in certain types of congenital hereditary deficiency several hepatic enzymes, such as Gilbert's syndrome;
- with tumor processes in this area;
- with a shortage of vitamin B12.
Increased direct bilirubin in the blood plasma is characteristic of gallbladder disease.These include:
- tumor formation of the gall bladder and the papilla 12 duodenal ulcer;
- infectious changes;
- inflammatory reactions;
- accumulation of parasites.
case of violation of the outflow of bile ducts by bilirubin in the stool decreases.The feces then become characteristic whitish color.
What is dangerous high bilirubin?
Increased blood concentration of the pigment may lead to toxic effects.Their appearance is due to several mechanisms:
- penetrating into cells, it affects the respiratory cycle and leads to their death.If there
- exceeding the critical level of the product breakdown of hemoglobin, it can penetrate the blood-brain barrier in the nervous system.Acting on neurons, it leads to the development of toxic encephalopathy, and in severe cases - and to coma.
hyperbilirubinemia usually accompanied by the following symptoms:
- staining of the skin and mucous membranes yellow of various shades;
- intolerable itching;
- neurological disorders in the form of weakness, headaches, irritability;
- dyspeptic symptoms;
- discoloration of feces and urine.
order to bring performance back to normal bilirubin level, the focus should be on treating the underlying disease.
In addition, to accelerate the excretion of toxic metabolites is possible by means of forced diuresis or by plasmapheresis.
Only by understanding what bilirubin, and which its fractions vary with the specific diseases, you can use this analysis to diagnose pathological conditions.