Hemolysis


Hemolysis

Hemolysis (or haemolysis)—from the Greek Hemo-, Greek "Polytonic|Αἷμα" meaning blood, -lysis, meaning to break open—is the breaking open of red blood cells and the release of hemoglobin into the surrounding fluid (plasma, "in vivo").

"In vivo" hemolysis

"In vivo" hemolysis, which can be caused by a large number of conditions, can lead to anemia.

Anemias caused by "in vivo" hemolysis are collectively called hemolytic anemias.

"In vitro" hemolysis

"In vitro" hemolysis can be an important unwanted effect in medical tests and can cause inaccurate results, because the contents of hemolysed red blood cells are included with the plasma. The concentration of potassium inside red blood cells is much higher than in the plasma and so an elevated potassium is usually found in biochemistry tests of hemolysed blood. If as little as 0.5% of the red blood cells are lysed the serum will have a visually obvious pinkish colour, due to hemoglobin.

Most causes of "in vitro" hemolysis are related to specimen collection. Difficult collections, unsecure line connections, contamination, and incorrect needle size, as well as improper tube mixing and incorrectly filled tubes are all frequent causes of hemolysis. Excessive suction can cause the red blood cells to be literally smashed on their way through the hypodermic needle owing to turbulence and physical forces. Such hemolysis is more likely to occur when a patient's veins are difficult to find or when they collapse when blood is removed by a syringe or a modern vacuum tube. Experience and proper technique are key for any phlebotomist or nurse to prevent hemolysis. "In vitro" hemolysis can also occur in a blood sample owing prolonged storage or storage in incorrect conditions (ie too hot, too cold).

Hemolysis due to mechanical blood processing during surgery

In some surgical procedures (especially some heart operations) where substantial blood loss is expected, machinery is used for intra-operative blood salvage. A centrifuge process takes blood from the patient, washes the red blood cells with normal saline, and returns them to the patient's blood circulation. Hemolysis may occur if the centrifuge rotates too quickly (generally greater than 500 rpm)—essentially this is hemolysis occurring outside of the body. Unfortunately, increased hemolysis occurs with massive amounts of sudden blood loss, because the process of returning patient's cells must be done at a correspondingly higher speed to prevent hypotension, pH imbalance, and a number of other hemodynamic & blood level factors.

Hemolysis in microbiology

Hemolytic patterns of the various Gram positive cocci; Streptococci are differentiated by hemolysis of red blood cells on blood agar (BA) plates.
*Alpha hemolysis is shown by a greenish halo around the colony and is the result of hemoglobin oxidation to methaemoglobin in red blood cells.
*Beta hemolysis is shown by a clear halo around the colony and is produced by complete hemolysis of the red blood cells.
*Gamma hemolysis is shown as no hemolysis or discoloration of the blood.

ee also

*Hemolysin

External links

* [http://www.calgarylabservices.com/HealthcareProfessionals/SpecimenCollection/HemolysisEffects.htm Effects of Hemolysis on Clinical Specimens]


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Look at other dictionaries:

  • hemolysis — n. The lysis of erythrocytes with the release of hemoglobin; the breaking apart of red blood cells in the blood. Syn: haemolysis, hematolysis, haematolysis. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • hemolysis — hemolysis. См. гемолиз. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • hemolysis — [hē mäl′ə sis, hē΄mō lī′sis] n. [ HEMO + LYSIS] the destruction of red corpuscles with liberation of hemoglobin into the surrounding fluid hemolytic [hē΄mō lit′ik, hem΄əlit′ik] adj …   English World dictionary

  • hemolysis — (he mol ī sis) The disruption of red blood cells and release of their hemoglobin. There are several types of hemolysis when bacteria such as streptococci and staphylococci grow on blood agar. In a hemolysis, a narrow greenish zone of incomplete… …   Dictionary of microbiology

  • hemolysis — hemolytic /hee meuh lit ik, hem euh /, adj. /hi mol euh sis/, n. the breaking down of red blood cells with liberation of hemoglobin. Also called hematolysis. [1885 90; HEMO + LYSIS] * * * ▪ physiology also spelled  Haemolysis,        breakdown or …   Universalium

  • Hemolysis — The destruction of red blood cells which leads to the release of hemoglobin from within the red blood cells into the blood plasma. Etymology: The word hemolysis is made up of hemo , blood + lysis , the disintegration of cells. * * * Alteration,… …   Medical dictionary

  • hemolysis — hemolizė statusas T sritis chemija apibrėžtis Eritrocitų irimas ir hemoglobino išsiliejimas. atitikmenys: angl. hemolysis rus. гемолиз …   Chemijos terminų aiškinamasis žodynas

  • hemolysis — noun Etymology: New Latin Date: 1890 lysis of red blood cells with liberation of hemoglobin • hemolytic adjective …   New Collegiate Dictionary

  • hemolysis — n. [Gr. haima, blood; lyein, to dissolve] The breakdown or destruction of red blood corpuscles …   Dictionary of invertebrate zoology

  • hemolysis — noun The destruction of red blood cells, and subsequent release of hemoglobin, at the normal end of the cells life …   Wiktionary


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