The blood test is the most common type of laboratory research used for almost all diseases. The accuracy of the results depends not only on the preparation of the patient for the procedure, but also on the technique of blood sampling. Taking blood from a vein in a traditional way, that is, using a conventional syringe, involves such difficulties:
- duration of the procedure;
- blood reaction to the environment;
- blood passage through the needle two times;
- blood clotting in the needle;
- erythrocyte destruction;
- difficulty in observing the correlation of the amount of blood and reagent;
- getting blood on the hands of a laboratory assistant;
- damage test tubes, spill blood.
Advantages of the new method
Vacuum systems have a number of significant advantages over the usual method of venous blood sampling. Among them:
- safety and comfort both for the patient and for the laboratory assistant;
- less pronounced pain;
- vacuum tubes are hermetic and do not break;
- procedure time is about 10 seconds;
- exact compliance with the ratio of blood volume and reagent;
- for a short period of time, you can collect the material into several tubes, without needing to inject the needle again;
- reliable and simple labeling of tubes: for each type of analysis - a tube with a lid of a certain color, which eliminates the error in its selection;
- Convenience for transportation and centrifugation;The
- system is completely closed, there is no air access to the blood;
- does not need to transfer the received material to other containers;
- no direct contact with blood;
- does not need to open the lid of the tube when working with analyzers;
- possibility of an individual approach to patients: the set includes a set of different needles, which are used depending on the condition of the veins;
- simplicity of design and application;
- saving on reagents and disposal of test tubes.
What is the system like?
The closed system includes a vacuum tube with a lid, a double-sided needle, a needle holder. Depending on the purpose, they are filled with appropriate reagents. The configuration of the system may differ depending on the type of analysis, the condition of the patient's veins, the experience of the medical worker.
The vacuum system includes two-sided needles, differing in length and diameter.
. The vacuum transparent tubes are made of plastic. The covers consist of a plastic casing and a rubber stopper. They provide tightness and sterility, maintain the vacuum state for up to two years. To distinguish test tubes for different purposes, the plastic case has a certain color, depending on the filler composition: red, green, blue, purple, black, gray. There is an international standard for the color coding of reagents, which all colors used in vacuum systems must match.
- Tubes with a red lid contain a coagulant activator or do not have a filler. They are designed for biochemical analysis, bacteriological, immunochemical, for the determination of the blood group.
- The EDTA tube has a purple cap. It is intended for general analysis, genodiagnostics, immunochemistry.
- The blue lid indicates that the test tube contains sodium citrate. Used to check coagulation.
- In a test tube with a green lid there is heparin. With its help, a biochemical and immunochemical analysis is carried out.
- The black lid indicates that the reagent is sodium citrate, and it is intended for the determination of ESR.
- In a test tube with a gray cap is a glucose stabilizer and an anticoagulant, used to determine the level of sugar.
To take blood, depending on the patient's veins, needles of different types and sizes( length and diameter) are used. Usually two-sided needles are standard. One side of the needle is inserted into the patient's vein, the other is punctured by an elastic tube plug. In addition, butterfly needles and standard needles with a Lueur connection can be used. In this case, a lyu-adapter is needed. The needle-butterfly, equipped with protrusions, is used for thin and hard-to-access veins.
Holders come in three types: standard, elongated and automatically dropping the needle.
The vasketeiner has the same operating principle as a conventional syringe. Blood is collected by creating a vacuum in a test tube, resulting in a pressure drop that plays the role of a piston.
Vacuum systems make a venous blood sampling comfortable and safe for the medic and patient
How is it performed?
- The needle is opened immediately before taking blood.
- From the needle, from the rubber membrane side, the cap is removed, the needle is inserted into the holder and rotated to the stop.
- The holder is in the right hand, with the cannula held with the index finger. The vacuum tube is in the left hand.
- Needle pierced skin and vein. It is necessary to pay attention to the cannula, located between the holder and the needle. If the needle is in the vein, the blood will appear in the cannula.
- The tube is inserted fully into the holder from the inside. At the same time, an elastic membrane is pierced in its lid. Blood begins to enter the tube, thanks to the vacuum created in it.
- The required amount of material is collected, the tube is removed from the holder.
- If you need to take blood several times, the next test tube is inserted into the holder, following the order: biochemistry, prothrombin assay, general analysis.
- When the blood sampling is completed, the needle is removed from the vein, the site of the prick is clamped with a cotton swab dipped in alcohol.
The appearance of the tube
can be seen in appearance. Classification
Vacuum tubes differ by the following features:
- size( length and diameter);
- appointment( hematologic, biochemical, blood coagulation analysis, etc.);
- reagent filling the tube;
- sample volume;
- type of cover.
How much blood can be delivered?
On filling the tubes are distinguished as follows:
- containing sodium citrate - designed to conduct coagulation reactions;
- containing sodium citrate - to determine ESR;
- with EDTA K-2;
- with EDTA K-3;
- containing a blood clotting activator and gel;
- without filler.
Price of vacuum tubes depends on the material of manufacture, volume and filling. Their approximate cost is:
- with sodium citrate - from 7.5 to 11 rubles apiece, depending on the volume;
- with EDTA K-2 and EDTA K-3 - from 7.5 to 10.5;
- with a clotting activator - from 7.5 to 8.5;
- with activator of coagulation and gel - from 10,5 to 13,5.
Two-sided vacuum needle standard costs about 6 rubles, the same price for a needle with a transparent cannula and a butterfly needle with a Luer adapter. The cost of the needle holder is about 4 rubles apiece.
The use of closed vacuum systems in the collection of venous blood is gradually replacing the traditional method. The new method is more effective, convenient and safe for patients and physicians. Vacuum syringes allow you to take blood and carry out the research in the shortest possible time, with the result being the most accurate.