Blood clotting time( by suharev)
The beginning of blood coagulation in a healthy person - from 30 seconds to 2 minutes, the end - from 3 to 5 minutes. Blood is taken from the finger into a clean and dry capillary from the apparatus of Panchenkov. The first drop of blood is removed with a swab, then a column of blood 25-30 mm high is inserted into the capillary and transferred to the middle of the capillary tube. Turn on the stopwatch and after every 30 seconds, tilt the capillary at an angle of 30-45 °.Blood freely moves inside the capillary. With the beginning of clotting, its movement slows down. At the time of complete clotting, the blood stops moving.
Blood coagulation time is an indicative measure of a multistage enzymatic process, as a result of which soluble fibrinogen passes into insoluble fibrin. This indicator characterizes the process of coagulation as a whole and does not give an opportunity to reveal the mechanisms leading to its violation. However, the time for blood clotting can be shortened only by accelerating the formation of blood prothrombinase( I coagulation phase - increased contact activation, a decrease in the level of anticoagulants).Therefore, shortening the time of blood coagulation always indicates an increased formation of prothrombinase in the patient's body. Due to the fact that blood pro-thrombinase can be easily replaced by tissue clotting to enhance the processes of clotting, the formation of which terminates 2-4 times faster( in 1-2 minutes), the shortening of the clotting time is often caused by the appearance in the bloodstream of tissue thromboplastin due to mechanical damagestissues, burns, extensive operations, transfusion of incompatible blood, sepsis, vasculitis, etc. Shortening of the clotting time indicates the need for prevention of hypercoagulability, which often threatens thrombosis and trhomboembolic.
Blood clotting significantly slows down due to congenital or acquired deficiency of prothrombogenesis factors( primarily VIII, IX and XI), with an increase in the blood concentration of anticoagulants, as well as degradation products of fibrinogen and fibrin( PDF).The pathological changes in blood clotting time according to Sukharev are reflected in the table.
Table Diseases and conditions accompanied by changes in clotting time
Table Diseases and conditions accompanied by changes in clotting time