To date, it is impossible to imagine medicine without biochemical studies of serum or plasma, since the tests conducted are more informative for doctors than complaints and the patient's well-being. Almost immediately after applying for help in the clinic or entering the hospital for treatment, the doctor appoints research of this kind. However, obtaining reliable data on the patient's health is based not only on modern equipment and quality reagents of medical laboratories. Of great importance is the correct blood sampling from the vein. The algorithm of manipulation and preparation of the patient to take biological liquids are of paramount importance in the diagnosis and the further appointment of the right treatment.

Preparation for research

It is not necessary immediately after a conversation with the attending physician to run to the biochemical laboratory or manipulation room for blood donation. Most likely, nothing will be taken in the manipulation room, as it is necessary to undergo a little preparation to draw blood from the peripheral vein. The algorithm of this preparation is as follows. On the eve before the manipulation should not be very tight dinner.

The correct algorithm for blood sampling from the vein

Food should be light, and dinner - no later than 19 or 20 pm. Too thick, fatty, spicy food can change the biochemical parameters of the blood, which can lead to incorrect results. In addition, in the morning, before the study itself, it is not necessary to have breakfast, as the blood surrenders on an empty stomach.

Equipment necessary for blood sampling from the vein

Depending on what equipment will be used to take blood, the list of necessary materials may vary, as the technique of blood sampling from the vein is somewhat different. The algorithm of manipulations remains practically the same. When fencing with an ordinary syringe will require:

  • burn;
  • cotton wool or cotton swabs;
  • antiseptic (70% alcohol);
  • disposable sterile syringe;
  • sterile medical tray;
  • napkins;
  • medical overalls;
  • test tubes.

If an algorithm is used to draw blood from the vein using a vacuum system, the need for test tubes and a disposable sterile syringe is eliminated. In addition, in the manipulation room should be present: patient chair, refrigerator, tripods for the installation of test tubes.

General rules for preparing for a blood sampling procedure

Before venipuncture is performed, the algorithm for blood collection from the vein must be communicated to medical personnel. Before doing the practical part, you need to wash your hands, which is mandatory for hygiene. After that, you should wear a robe, as well as other protective medical clothing. After the medical staff is ready for the procedure, the patient is invited to the manipulation room. The direction to the blood sampling is registered, as well as the identification of the patient. After this, an explanation of the upcoming procedure is carried out, the patient is seated in a chair, necessary equipment is prepared and the procedure for venipuncture is prepared.

Preparation of venipuncture site

After all the equipment is prepared, the nurse starts to perform the manipulation for blood collection. For this, the elbow vein is most often used (due to its superficial location and accessibility). It is necessary to choose the intended site for the puncture, examine it and palpate the vessel. After this, apply a tourniquet above the site of the intended puncture. The tourniquet should be applied in such a way that it does not squeeze the arterial vessels, and the outflow of blood through the veins stops. Next, the patient should be asked to squeeze the hand several times to strengthen the blood flow. If, for any reason, the patient does not manage to squeeze his hand into a fist, a warm water bottle can be applied to the prospective venipuncture site. Heat will promote the expansion of blood vessels and blood flow will increase.

After the disinfection of the puncture site. To do this, using a sterile gauze or cotton swab in a circular movement, directed from the center to the periphery, processing the surface of the skin. The treatment is carried out twice and the complete drying of the antiseptic solution is awaited. After treatment, palpation of the venous vessel is not performed.

The algorithm for blood collection from a vein using a disposable syringe

To carry out the procedure, prepare the necessary equipment and open the syringe. In this case, the package with a syringe is held in the left hand with a transparent side of itself with a spout down. An autopsy is performed by a momentary rupture of the paper part about the syringe piston with the right hand moving away from itself. Next, without removing the syringe completely from the package, put on the needle for injections. To do this, take the product behind the piston and the side ears and insert it into the needle. After the injection needle is worn on the nozzle of the syringe, the packaging can be completely removed.

A needle guard is removed from the needle and a vein puncture is performed. At the time of penetration of the needle into the vessel, there is a sensation of falling into the void, and a small amount of blood appears in the nozzle of the syringe. Control of the position of the needle is carried out by pulling the piston toward you, while the syringe must receive venous blood. Then the algorithm for performing blood sampling from the vein is as follows. If blood arrives, the position of the syringe and the needle relative to the vessel is fixed, and slowly continue to pull the piston onto itself until the required amount of blood is obtained. After that, remove the tourniquet and remove the syringe and needle from the vessel. Place the puncture with a sterile cotton or gauze pad moistened with a solution of antiseptic.

The patient is then asked to bend his arm at the elbow joint. The needle from the syringe is dumped into a container, and the blood on the wall is poured into a test tube. After all the blood is in the test tube, the syringe is ejected into a container with a disinfectant. Summing up the above, it is necessary to say that if the blood is taken from the vein, the algorithm of action and skills should be perfectly worked out in theory and in practice.

The algorithm for blood collection from a vein using a vacuum system

To date, technological progress, including in medicine, does not stand still. Instead of an ordinary syringe, you can draw blood from the vein by a vacuum system. The algorithm in this case is not very different from that of blood sampling using a syringe. When carrying out blood sampling with a vacuum system, prepare a needle for puncture and insert it into the holder. Grabbing the patient's forearm with the left hand 3-5 cm below the intended place of needle insertion, tighten the skin and perform venipuncture. The needle and the holder are inserted under an approximate angle of 15 degrees.

If there is a vein in the indicator chamber of the needle, blood appears. After this, the tube is placed into the holder and the blood is drawn from the vein by the vacuum system. The algorithm is the following: fix the position of the needle and the holder in the vessel, and with the right hand, by pressing it to the bottom of the tube, it is inserted into the holder. If the tube is working, after installation, blood begins to flow into it.

After filling, the tube is removed from the holder. When taking blood in several tubes, the correct order of filling should be observed. At the end of the blood sampling procedure, the needle and the holder are removed, a sterile cloth moistened with antiseptic is applied to the puncture site, or a bactericidal plaster is applied.

Blood sampling tubes are marked appropriately: they indicate the patient's name and surname, age and identification number. In the case of using an automated system for biochemical analysis, an identification bar code is pasted onto the tube. Thus, the algorithm of blood sampling from a vein by a vacuumer looks like.

It should be noted that, as in the case of blood sampling with a syringe, once the vein is punctured and the blood begins to flow into the syringe or test tube, the tension of the harness should be weakened. Prolonged clamping can lead to changes not only in the protein and electrolyte composition of the blood, but also in clotting and gas composition. Carrying for the first time a vacuum blood sampling from a vein, the algorithm of actions should be debugged on the layout for training, so as not to allow mistakes in the process of real execution.

Blood sampling in children

The algorithm for blood collection from a vein in children does not differ from that in adults. The only thing to consider when carrying out this type of manipulation is that children are in every way afraid of such procedures. Therefore, if the collection of blood in children is constant, you need to take care of the presence of distractions for the child (for example, bright and colorful toys or multimedia panels). When you switch attention, the child will not be so focused on what is happening.

Complications arising from the collection of blood from the vein

Particular attention should be paid to possible complications after venipuncture. To avoid them, you must carefully follow the rules of asepsis and antiseptics, as well as clearly perform the algorithm of venipuncture. Only a clear adherence to the algorithm will help to avoid hematomas and the occurrence of infectious and inflammatory processes at the injection site.


The algorithm of blood sampling from the vein is a guarantee not only for the absence of complications after the venipuncture procedure itself, but also for obtaining reliable results of biochemical studies.