Factor V (proaccelerin)
Last reviewed: 23.04.2024
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The reference values (norm) of the factor V activity in blood plasma are 0.5-2 cd / l or 60-150%.
Factor V (proaccelerin) is a protein fully synthesized in the liver. Unlike other factors of the prothrombin complex (II, VII and X), its activity does not depend on vitamin K. It is necessary for the formation of internal (blood) prothrombinase, activates factor X for the conversion of prothrombin to thrombin. In cases of factor V deficiency, the external and internal pathways for the formation of prothrombinase are disturbed to varying degrees. In the coagulogram this is manifested by an increase in prothrombin time; APTTV and thrombin time remain within normal limits.
Indirect anticoagulants do not have a significant effect on the content of factor V in the blood.
Determination of the activity of pro-acetylin is used to detect its congenital and acquired deficiency.
Hereditary deficiency of factor V is manifested by paragemophilia (Ovren's disease).
The activity of factor V is markedly reduced in severe forms of acute viral hepatitis and in the transition of acute hepatitis to chronic. With cirrhosis of the liver, a distinct decrease in the proacceleurin content in the blood plasma is observed. With uncomplicated mechanical jaundice, the activity of factor V decreases, but is insignificant; with secondary involvement in the process of the liver there is a distinct decrease in the activity of factor V.
The minimum hemostatic level of activity of factor V in the blood for performing operations is 25%, with a lower content the risk of postoperative bleeding is extremely high. The minimum level of activity of factor V in the blood to stop bleeding is 5-15%, with a lower content of bleeding stopping without the introduction of a factor V patient is impossible. With DIC-syndrome, starting with the II stage, there is a distinct decrease in the activity of factor V due to its consumption.
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