WS/T 661-2020Guidelines of venous blood specimen collection (English PDF)

4.1 Diet

4.1.1 Patients should not change their eating habits before blood sampling, and should not drink alcohol within 24 hours.

4.1.2 The test items that require fasting blood sampling include (not limited to).

a) Glucose metabolism. fasting blood glucose, fasting insulin, fasting C-peptide, etc.;

b) Blood lipids. total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A1, and Lipoprotein B, lipoprotein a, apolipoprotein E, free fatty acids, etc.;

c) Hemorheology (blood viscosity);

d) Bone metabolism markers. osteocalcin, type I collagen carboxyl terminal peptide beta special sequence, bone alkaline sulfatase, etc.;

e) Platelet aggregation rate (turbidimetric method).

Fasting requires at least 8 hours of fasting, preferably 12 hours to 14 hours, but not more than 16 hours. It should be arranged to collect blood from 7.00 to 9.00 am.

Drink a small amount of water during fasting.

4.2 Movement and mood

24 hours before blood collection, the patient should not exercise vigorously. The patient should avoid being emotional on the day of blood collection, and rest for at least 5 minutes before blood collection. If needed Take blood after exercise, follow the doctor's advice and inform the inspector.

4.3 Blood collection time

Test items with special requirements for blood collection time include (not limited to).

a) Blood culture. At the beginning of chills or fever, it is best to collect before antibiotics. For other special requirements, see WS/T 503;

b) ACTH and Cortisol. Physiological secretion is circadian rhythm, routine blood collection time points are 8.00, 16.00 and 24.00;

c) Female sex hormones. There are significant differences in the different stages of the menstrual cycle. The date of blood collection should follow the doctor's advice. Check the menstrual cycle with the patient before blood collection;

d) Drug concentration monitoring. The specific blood collection time should follow the doctor's advice, and the patient should check the last administration time before blood collection;

e) Oral glucose tolerance test. normal diet 3 days before the test, blood was collected on an empty stomach on the test day, and then 75 g of anhydrous glucose (phase when 82.5 g (containing dextrose monohydrate) is dissolved in 300 ml of warm water, drink it within 5 minutes. Time the first oral sugar, and Blood is collected at 2 hours. Blood collection at other time points should follow the doctor's advice;

f) Other functional tests. blood is collected at the time set by the functional test protocol recommended by the relevant clinical guidelines;

g) Blood Plasmodium examination. The best time for blood collection is when chills occur.

4.4 Blood collection position

Blood is collected in sitting position for outpatients and supine position for patients in ward. The position of certain test items (such as renin, angiotensin, aldehyde the test results of sterone, etc.) have a significant impact, and blood should be collected in the position required by the doctor.

4.5 Infusion

Blood should be collected 3 hours after the end of the infusion; for the slow metabolism of the infusion components and severely affect the test results (such as fat emulsion), it should be in the next infusion Take blood before injection. In an emergency, when blood must be collected during infusion, it is advisable to collect blood from the contralateral limb or the distal end of the infusion point of the ipsilateral limb, and inform the inspector.

5.1 Preparation of blood samples

5.1.1 Blood collection tube

Vacuum blood collection tubes should be used. Refer to Appendix A for commonly used vacuum blood collection tube types, additives and applicable detection ranges.

5.1.2 Blood collection needle

A straight needle should be used routinely for blood sampling. When collecting blood culture specimens, butterfly wing needles should be used.

According to the characteristics and location of the vein, the appropriate blood collection needle size should be selected, and 22 G blood collection needle should be used. Coagulation function and platelet function for relevant detection, blood sampling needles of 21 G and below should be used when the blood volume is greater than 20 ml.

It is advisable to use safe blood collection needles that can minimize occupational exposure. If a syringe is used to collect blood, it should be equipped with a transfer device, and make Relevant procedures for reducing occupational exposure risks.

5.1.3 Tourniquet

If conditions permit, a snap-on tourniquet should be used; if a non-disposable tourniquet is used, standard disinfection should be carried out after each use.

5.1.4 Disinfectant

Disinfectants that can be used include (not limited to). iodine tincture and isopropanol compound preparation, chlorhexidine gluconate, povidone iodine and ethanol compound Preparation, compound preparation of iodine, chlorhexidine acetate and ethanol, 75% medical alcohol, etc.

5.1.5 Hemostatic products

Sterile cotton balls, gauze or cotton swabs, hypoallergenic medical tape, etc.

5.1.6 Pad towel

Should choose disposable pad towel or sterile pad towel.

5.1.7 Sharps Box

The sharps box should be used once, and the use volume should not exceed 3/4.

5.1.8 Personal protective equipment

Medical gloves, masks and hats, etc.

5.2 Personal protection

Wear a medical cap, mask and gloves before starting blood collection. It is advisable to replace new gloves after completing the collection of blood samples from each patient;

It is not allowed to use quick-drying hand disinfectant for disinfection at least after the completion of the blood sample collection of each patient; such as the contamination of gloves during blood collection Blood or breakage should be replaced in time. For example, if the blood sampling target is multi-drug resistant bacteria infection, respiratory infectious disease, blood-borne infectious disease and has blood, body for patients at risk of liquid splashing, personal protection should be carried out in accordance with WS/T 311 and GBZ/T 213.

5.3 Confirmation of patient identity and preparation

5.3.1 Patient identification

Check the patient's name, gender, age, hospitalization number, medical card, ID card and other information to ensure that the patient is the person whose blood was collected. Should make Use unique information such as hospitalization number (wristband used by qualified units), medical card, ID card, or at least two types of non-unique information.

5.3.2 Confirmation of patient readiness

For test items with special requirements such as diet, exercise, time, body position, drugs, etc., check and confirm the relevant information according to the doctor's advice before blood sampling.

5.3.3 Confirmation of patient's allergy history and other contraindication information

Confirm whether the patient has latex allergy, banned iodine preparations, alcohol allergy or disabled, etc. For patients allergic to latex, you need to use Gloves, tourniquets, medical tape and other items that do not contain latex materials. For patients who ban iodine-containing preparations, 75% medical alcohol or Disinfect other disinfectants without iodine. For patients who are allergic to or prohibited from alcohol, use iodine, hydrogen peroxide and other non-alcoholic disinfectants for disinfection.

5.4 Information mark of blood collection tube

Select the number and type of blood collection tubes according to the test items, and mark the patient and test item information. Electronic barcodes should be used for information marking.

5.5 Exposure of the blood collection site

5.5.1 Blood sampling in the sitting position. ask the patient to sit sideways, with the upper body perpendicular to the ground, place the arm on a stable operating table, and place the elbow on the pad on the towel, make the upper arm and forearm in a straight line, and the palm is slightly lower than the elbow, fully exposing the blood sampling site.

5.5.2 Recumbent blood collection. ask the patient to lie on his back, make the upper arm and forearm in a straight line, the palm is slightly lower than the elbow, fully expose the blood collection site.

5.5.3 Inform the patient that it is not advisable to wear a shirt with tight cuffs to reduce bleeding and hematoma after blood sampling.

5.6 Choice of puncture vein

The veins in the anterior elbow area of the arm are preferred, followed by the median vein, the cephalic vein and the expensive vein.

When it is not possible to collect blood from the veins in the front of the elbow, the superficial veins on the back of the hand can also be selected. Severe body edema, extensive burns, etc.

When patients cannot find a suitable puncture vein in their limbs, they can choose to collect blood from superficial cervical veins and femoral veins.

The veins on the inside of the wrist should not be used, as the puncture is painful and easily damages nerves and tendons. It is not advisable to use the veins at the ankle, it may it can cause complications such as phlebitis and local necrosis. Other unsuitable veins include. the veins of the ipsilateral upper limb after radical mastectomy (3 Months later, blood collection can be resumed without special complications), the veins after the injection of chemotherapy drugs, the blood vessels in the arm of the arteriovenous fistula of hemodialysis patients, There are skin lesions, inflammations, scabs, and scars at the puncture site.

5.7 Tying a tourniquet

The tourniquet should be tied 5 cm~7.5 cm above the blood collection site. It is advisable to loosen the tourniquet when the first tube of blood is collected. Use time it should not exceed 1 min. If the tourniquet needs to be used for more than 1 min in one part in some cases, it is advisable to loosen the tourniquet and wait for 2 minutes before renewing New lashing. If the skin where the tourniquet needs to be tied is damaged, it is advisable to choose another blood collection site.

During the puncture, the patient can clenched fists (do not repeatedly tap the blood collection site) to make the vein more filled, which is beneficial to the successful puncture. Successful puncture Afterwards, let the patient relax his fists and try to avoid repeated clenching movements.

Note. If venous blood test (arterial blood test is preferred) for lactic acid, blood should be collected without a tourniquet, or the tourniquet should be released after successful puncture and wait for blood Collect after flowing for at least 2 min.

5.8 Disinfection

With the puncture point as the center, the disinfection is performed in a circular manner from the inside to the outside, and the disinfection range is 5 cm in diameter, and the disinfection is performed twice. Disinfectants need to work Keep in contact with the skin for at least 30 s, and puncture after natural drying to prevent hemolysis and burning of the specimen. If venipuncture is difficult, After poisoning, you need to touch the position of the blood vessel again. It is advisable to puncture the blood collection site after disinfection again.

See WS/T 503 for the collection and disinfection requirements of blood culture specimens.

5.9 Venipuncture and blood specimen collection

5.9.1 If using a blood collection system, follow the product instructions.

5.9.2 When using a vacuum blood collection system, assemble the blood collection needle and needle holder according to the instructions; if a syringe is used to collect blood, it should be Before making sure that the air in the syringe is exhausted.

5.9.3 Hold the patient's arm under the puncture site, and pull down the skin to fix the vein with the thumb at 2.5 cm~5.0 cm below the puncture point.

Avoid touching the disinfected area.

5.9.4 Keep the needle oblique face up, so that the blood sampling needle is inserted into the vein at an angle of about 30° with the arm. After successfully puncturing the vein, you can Continue to advance in the vein along its direction to keep the blood sampling needle stable in the vein.

5.9.5 When using the vacuum blood collection system, push the first blood collection tube into the needle holder/connect to the blood collection needle (when using a straight needle to collect blood, use the needle holder's the scoliosis prevents the movement of the blood collection needle in the vein). Wait for the blood collection tube to be exhausted and blood flow to stop, then pull out the blood collection tube from the needle holder/blood collection needle.

To ensure sufficient blood volume and the correct ratio of blood to additives. When the collection continues, the next blood collection tube can be pushed into the needle holder/connector Receive the blood sampling needle, and repeat the blood sampling process. When using a syringe to collect blood, it is advisable to withdraw the needle rod slowly and uniformly until the piston reaches the end of the syringe.

5.9.6 The collection sequence of different blood collection tubes is as follows.

a) Blood culture bottle;

b) Sodium citrate anticoagulant blood collection tube;

c) Serum blood collection tubes, including coagulant and/or separating gel;

d) Heparin anticoagulation blood collection tube with or without separating glue;

e) EDTA anticoagulation blood collection tube with or without separating glue;

f) Glucose digestion inhibits blood collection tube.

Note 1.The blood collection tube used for molecular detection should be collected before the heparin anticoagulation blood collection tube to avoid possible heparin contamination that may cause the PCR reaction to be inhibited.

Note 2.Blood collection tubes used for trace element detection should fully consider whether the additives in the front blood collection tube contain the detected trace elements, and collect them separately if necessary;

It is not advisable to use a syringe for collection.

When a butterfly wing needle is used and only sodium citrate anticoagulation specimens are collected, the first blood collection tube should be discarded. The discarded blood collection tube is used for the prefilling blood collection group the pipeline of the piece does not need to be completely filled.

If a syringe is used to collect blood, the sequence of transferring blood from the syringe to the vacuum blood collection tube is the same as that of the vacuum blood collection system. Do not it is advisable to remove the rubber plug of the vacuum blood collection tube. It is not suitable to apply pressure to the syringe needle and let the blood flow into the blood collection tube by itself until the blood flow stops.

Ensure the correct ratio of blood to additives and reduce the occurrence of hemolysis.

In special circumstances, when blood can only be collected from a venous indwelling tube, the initial 5 ml or 6 times the lumen volume of blood should be discarded for the coagulation function test.

For other tests, it is advisable to discard the first 2 times the lumen volume of blood.

5.9.7 Blood collection tubes containing additives should be gently inverted and mixed immediately after blood collection. The mixing frequency should be in accordance with the requirements of the product instructions.

Do not shake vigorously to avoid hemolysis.

5.9.8 Handling when blood samples cannot be collected normally

Slightly adjust the needle entry position. If the blood sampling needle penetrates too deeply into the vein, it can be slightly withdrawn. If the puncture is not enough, the blood sampling needle can be slightly pushed into the vein Into. It is not advisable to blindly explore when the vein direction is unknown.

If the puncture is successful and the blood flow suddenly stops during the collection, it may be that the needle hole is attached to the blood vessel wall, and the blood collection needle can be rotated half a circle.

If it is suspected that the vacuum of the vacuum blood collection tube is insufficient, the blood collection tube should be replaced in time.

5.9.9 Treatment in case of suspected artery or nerve injury

During the blood collection process, if a hematoma is rapidly formed at the puncture site or the blood collection tube is quickly filled, and it is suspected that the artery has been punctured, the blood collection should be immediately terminated and removed Take out the blood collection needle and press the blood collection site for 5 min to 10 min until the bleeding stops. If necessary, venipuncture can be performed in other parts.

During blood collection, if the patient feels radioactive electric shock-like pain, tingling or numbness at the proximal or distal end of the puncture site, suspect Puncture the nerve, immediately stop blood sampling and pull out the blood sampling needle to stop bleeding. If necessary, venipuncture can be performed in other parts. If necessary, please clinical the doctor evaluates and treats the patient's nerve damage.

5.9.10 Emergency treatment of patients with syncope

If the patient faints during the blood collection process, it is advisable to stop the blood collection immediately and pull out the blood collection needle to stop the bleeding; place the patient in the supine position and loosen the collar;

If the patient is suspected of taking blood on an empty stomach and hypoglycemia, oral sugar can be given; observe the patient's recovery of consciousness and vital signs such as pulse, respiration, and blood pressure.

If vital signs are unstable, call emergency personnel immediately. Qualified units can configure automatic external defibrillators at blood collection points and train staff to use them.

5.9.11 Preventing specimen hemolysis

Precautions for preventing hemolysis of specimens are as follows.

a) The puncture site is naturally dry after disinfection;

b) Do not collect blood through the hematoma;

c) If a syringe is used to collect blood, ensure that the needle is firmly installed on the syringe to prevent foam;

d) Avoid pulling the needle with excessive force when using the syringe;

e) Mix the specimens containing additives by gently inverting.

5.10 Needle withdrawal and puncture point to stop bleeding

First loosen the tourniquet, pull out the last blood collection tube from the blood collection needle/needle holder, and pull out the blood collection needle from the vein. After pulling out the lancet, Cover the puncture site with sterile cotton swabs, cotton balls or gauze, etc., and press the puncture point for 5 minutes (patients with abnormal hemostatic function should extend the time appropriately), Until the bleeding stops. It is not advisable to bend the elbow and press, which will increase the extra pressure, leading to an increased risk of bleeding, congestion, and pain. Such as Under the premise of correct compression to stop bleeding, if hematoma occurs or the bleeding lasts for more than 5 minutes, clinicians can be asked to evaluate and treat the patient's coagulation function.

For hematomas or bruises that have formed, cold compresses can be given within 24 hours to stop bleeding to avoid lifting heavy objects on the side limbs, and hot compresses can be applied after 24 hours to promote the absorption of congestion.

5.11 Medical waste treatment

Follow the "Medical Waste Management Measures for Medical and Health Institutions" and GBZ/T 213 requirements.

If you use a vacuum blood collection system, you should turn on the safety device according to the manufacturer's instructions, and discard the blood collection needle into the sharps box. If using note Injector, the needle should not be re-covered with the protective sheath, and the needle should not be bent, broken, or cut, nor should it be removed from the syringe.

Dispose of cotton balls, cotton swabs, gauze, etc. used for disinfection and hemostasis in a waste bin with biohazard signs.

5.12 Blood collection time record

Immediately after the blood collection is completed, use written or electronic records to correctly record the time of blood sample collection.

6.1 Storage and transportation requirements

Venous blood samples should be sent for testing in time after collection, and testing and centrifugation of serum/plasma should be completed within 2 hours (except for whole blood testing samples).

For test items that require special conditions for storage and transportation, such as body temperature (37 °C), refrigeration (2 °C ~ 8 °C), freezing (-20 °C), Avoid light, etc. It is advisable to refer to the storage conditions reported in the relevant literature or conduct stability assessment. Refer to WS/T 503 for the transportation and storage requirements of blood culture specimens.

6.2 Se...