Cyanosis

When cyanosis (from Greek κυάνεος "blue" ) is called in medicine violet to bluish discoloration of the skin, mucous membranes, lips and fingernails. The particular tint must not in all these areas simultaneously or occur equally strong. Cyanosis may, in acute occurrence, be a symptom of a dangerous or life- threatening disorder of the organism or, for longer existence, also a model for chronic diseases.

Causes

The cause of cyanosis is usually a deficiency of the blood with oxygen, either by insufficient intake option, as in too low a concentration of oxygen in the air, or by too long diffusion distances in pathological changes in the lung. The bluish staining resulting from the oxygen-dependent coloring of hemoglobin. During oxygen-rich ( oxygenated ) hemoglobin is bright red, appears low in oxygen ( deoxygenated ) hemoglobin dunkel-rot/blau. Visible cyanosis is usually from about 5 g of deoxygenated hemoglobin (Hb ) in 100 ml of blood.

Cyanotic states may be or incidental or sequelae of heart failure, such as the pulmonary edema, also arise symptoms of heart failure.

A trigger for cyanosis may also be a high dose of the antioxidant propyl gallate ( E310 ).

Zyanoseformen

A distinction is made between peripheral ( Ausschöpfungszyanose ) and central cyanosis ( Mischungszyanose ) which may be present simultaneously.

Peripheral cyanosis

Due to increased oxygen utilization in the periphery of the body due to slow blood flow it comes to peripheral cyanosis. It should be read primarily by a discoloration of the peripheral parts of the body such as the skin and the extremities. It can be the cause due to a decrease in the cardiac cardiac output (heart failure ), through a venous thrombosis, varicose veins, neurally induced acrocyanosis or changes in the blood ( polycythemia, cold agglutinins, cryoglobulinemia ).

Central cyanosis

A central cyanosis occurs due to decreased oxygen saturation of the blood in the lungs and is reflected in a discoloration in particular the oral mucosa, tongue - which in this case also particularly represent the veins under the tongue a good sign of cyanosis - the lips and in other parts of the body. The cause is either pulmonary insufficient oxygenation of the blood in the lungs or cardiac mixing of oxygenated and deoxygenated blood in the heart due to a heart defect with shunting.

Can be distinguished peripheral and central cyanosis by controlling the tongue color: in peripheral cyanosis the tongue bluish discoloration not usually with central cyanosis cyanotic discoloration of the thing is to recognize.

The appearance of cyanosis as a result of shunt reversal with heart defects, which were not initially connected to a cyanosis is called Spätzyanose or Eisenmenger's reaction.

Methemoglobinemia as a cause of cyanosis

A special and relatively rare disorder that causes cyanosis, is the so-called methemoglobinemia. It is caused by an increased concentration of methemoglobin (Met -Hb, oxidized form of hemoglobin ) in the red blood cells. This may be due to a hereditary enzyme defect ( untreatable ) or be caused by the ingestion of substances that have an oxidizing effect on the red blood pigment, such as nitrites (see a poppers), chlorates, aromatic amines or an increased concentration of nitrates in food or drinking water of about 100 mg / l Met- Hb can not transport oxygen molecules and by the reaction loses the iron bound in hemoglobin its ability to store oxygen and release of organs and body parts. If the concentration of Met -Hb by more than 10 % of the total amount of hemoglobin (more than 70 to 80% are fatal), there is a lack of oxygen in the blood and it develops cyanosis. In a blood test, the chocolate-colored blood falls on. The skin is slate gray. Symptoms of oxygen deficiency in the blood are often dizziness, nausea, headache, accelerated heart rate, shortness of breath and dizziness (somnolence ). Especially for babies and toddlers is a dangerous methemoglobinemia and its effects are sometimes confused in these ages with the symptoms of heart failure. As a result, valuable time is lost during the therapy. Initially for the treatment of the harmful substance to be avoided.