Study of the hemostatic system
Selection of the necessary research methods determined by the specific clinical situation and the tasks, who decide to clinicians at the bedside.
Therefore, one set of tests used in the diagnosis hemorrhagic diathesis, others - with the recognition and treatment of DIC and thromboembolism, others - during the examination of newborn, fourth - during anticoagulant and fibrinolytic therapy, etc.. d.
Performing the same in all cases the same standard coagulation little information, satisfies neither the clinician, HN laboratory, often unreasonable burden and a large number of unnecessary laboratory investigations, preventing the application of other, sometimes very important.
Experience shows, what often recognition of a violation of hemostasis can be accomplished by the shortest route - with a few well-chosen test. However, this laboratory staff should be informed about the purpose of the research, clinical situation, We faced by clinicians, and of their tasks, t. it is. actively participate in the diagnostic process.
The choice of research methods, performed by the laboratory, It defined as its client profile hospitals. So, the centers or departments for the treatment of burns, infectious and septic diseases must be carried out all the research for the diagnosis and treatment of controlled intravascular coagulation (DIC, acute kidney failure and others.). but there is no need to build and execute tests, associated with the recognition of hemophilia and other inherited bleeding disorders.
Experience shows, that in large cities advisable to have one central laboratory, performing a study of all parts of the hemostatic system and bearing an advisory, educational-methodical and controlling the quality of the center, and a number of subsidiaries of specialized laboratories in hospitals, hospitals, etc.. d.
In deciding whether the organization should consider the following laboratories:
- study of many parameters of the hemostatic system should be carried out in the shortest possible time after the extraction of blood from the vein (during the first hour);
- hemostatic disorders often require rapid diagnosis;
- in transit, shaking the blood and hemolysis several studies significantly distorted. Some studies should be carried out directly in the wards - operating, at the bedside.
For the most accurate and reliable results, strict adherence to the rules for obtaining blood from a vein (without harness and massage), stabilization (silikonirovanie utensils, the correct ratio of blood and stabilizing solution), time intervals between receipt of blood and its research and t. d.
When choosing a laboratory techniques should be preferred for contact and standardized phospholipid activation tests, and therefore prior to the study of blood and plasma must be in siliconized dishes, and then to create the necessary contact activation is added kaolin, and phospholipid - Kefalonia. Without it, the rate of activation of the contact and the phospholipid becomes very choppy, which leads to widely varying results, since the contact activation leaves, as it is known 4/5 all clotting time.
Standardized methods not only more accurate, but also much more sensitive to a deficiency of coagulation factors. So, if the clotting time of whole blood and plasma recalcification already normalized when the content in the blood plasma of 4-5 % factors VIII or IX, the breach in the kaolin-kefalinovyh techniques detected and 15-20 % the level of these factors. A further increase in sensitivity is achieved by testing dilutions of the test plasma (10-20 times) with subsequent correction of the level of all factors, except determined. Based on this principle all methods for the quantitative determination of individual coagulation factors, and autokoagulyatsionny standardized test.
All of these methods are two-stage, since the activity generated in the diluted plasma thrombin tested them on a normal whole plasma or a solution of fibrinogen.
