What are the dangers of taking a blood sample from a vein?

1 The concept of air embolism: air embolism is a phenomenon caused by air entering the veins of the body and reaching the heart during the process of infusion or blood transfusion, as well as under human factors, causing blood circulation disorders. If the amount of air entering is small, it will not cause much harm; If the amount of air entering is large, it will cause severe hypoxia in the body, resulting in serious consequences of immediate death.

2 The process of air embolism: After the air enters the vein, it is first carried to the right atrium and then to the right ventricle along the veins. If the amount of air is low, it is pressed into the pulmonary artery by the right ventricle, dispersed into the pulmonary arterioles, and finally into the capillaries, so the damage is small; If the amount of air is large, with the beating of the heart, the air and blood are mixed into foam, and circulate to the whole body with the blood, such as entering the pulmonary artery, its branches can be blocked, so that the blood can not enter the lungs, causing severe hypoxia and causing death; If it enters the coronary arteries of the heart, it can block the coronary circulation, cause severe cardiac dysfunction, and cause death.

3. Factors causing air embolism: mainly caused by air entering the veins of the body when the air is not exhausted during infusion or blood transfusion, the rubber tube connection is not tight and there is a leaking seam, pressurized infusion or no one is guarding the side. Generally, it will not cause great harm to the human body, because cats need to inject 20 40 ml of air to cause embolism and death, dogs need about 80 150 ml of air, and people need more.

However, it can cause blood circulation disorders in local organs, resulting in hypoxia and abnormal function of local organs.

The following should be noted during the collection of venous specimens:

1) For biochemical testing, the patient should be notified in advance to collect specimens and filial piety on an empty stomach;

2) Prepare specimen containers according to different test purposes and calculate the amount of blood collected;

3) It is strictly forbidden to collect blood samples at the needles of infusion and blood transfusion; Call for judging.

4) Blood samples of several items should be injected into the blood culture flask first, then into the anticoagulant flask, and finally into the dry test tube, and the action should be fast and accurate.

Precautions for venous blood specimen collection:

For fasting blood draw, the patient should be notified in advance to fasting to avoid affecting the test results due to eating.

Specimen containers are selected according to the purpose of the test, and the amount of blood collected is calculated.

After blood collection, the syringe piston should be withdrawn to prevent blood clotting from causing needle blockage and syringe adhesion.

When taking several types of blood samples at the same time, attention should be paid to the injection sequence: generally the blood is injected into the blood culture flask first, then into the anticoagulant tube, and finally into the drying tube, and the action should be accurate and rapid.

When collecting blood culture specimens, aseptic operation should be strictly implemented to prevent contamination; The type and amount of culture medium should meet the requirements, and the cork should be kept dry.

Blood specimens are strictly forbidden to be drawn at the needle of infusion or blood transfusion or from the ipsilateral limb, and blood specimens should be collected from the contralateral limb.

Precautions for blood specimen collection:

1.In order to reduce the fluctuation of test results due to the time of blood collection, it is best to fix the same time for each blood collection;

2.The tourniquet compression time should not be too long, too long can easily cause changes in various components and intravascular hemolysis;

3.Avoid drawing blood as a sample to be tested during infusion and medicine;

4.Timely inspection.

1.Blood specimens should be taken on an empty stomach for biochemical tests to avoid affecting the test results due to ingestion.

2. It is strictly forbidden to take blood samples at the needles of infusion and blood transfusion, as the test results will be affected in the name of the name, and should be taken on the contralateral limb.

3. Aseptic techniques should be strictly implemented to prevent infection.

Precautions: Patients should be patiently explained before blood collection to eliminate unnecessary doubts and fears. In case of dizziness during needle insertion or after blood collection, the needle should be removed immediately and let him lie down for a while to recover.

If necessary, the patient can be given aromatic ammonia tincture, acupuncture (or thumb pinching) of Renzhong and Hegu acupuncture points. If dizziness is induced by hypoglycemia, the patient can be immediately injected with intravenous glucose or instructed to take oral sugar water, and if there are other conditions, the doctor should be immediately treated; Hemolysis of blood specimens should be prevented. The causes of hemolysis include the syringes and containers that are not dry and clean; The strapping time of the pulse pressure belt is too long, and the blood stasis is too long; Poor puncture and excessive tissue injury; Specimens after hemolysis not only reduce the red blood cell count and hematocrit, but also change the chemical composition of the serum (plasma), so it must be avoided, and in order to avoid bruising and concentration, the compression time of the pulse pressure zone should not be too long, preferably no more than 30 seconds:

When drawing blood, it can only be pulled outward, not pushed inward, so as not to inject air into an air embolism, causing serious consequences.

Formal and accurate operation needs to pay attention to:1The blood collection person must be fasting, so that the measured value will be more accurate; 2.The person collecting the blood must collect the blood at rest; 3.The blood collection operator must strictly follow the steps of aseptic operation.

First of all, do a good job of explanation, strict aseptic operation, collect sufficient blood volume, master the time of blood collection, and send it for testing in time.

Precautions for blood specimen collection copy:

1.In order to reduce the fluctuation of test results due to the time of blood collection, it is best to fix the same time for each blood collection;

2.The tourniquet compression time should not be too long, too long can easily cause changes in various components and intravascular hemolysis;

3.Avoid drawing blood as a sample to be tested during infusion and medicine;

4.Timely inspection.