Blood lancets are specialized medical devices used for collecting blood samples. They must be operated by professionally trained medical personnel (such as nurses and doctors) in medical institutions (hospitals, clinics, physical examination centers, etc.) in accordance with standardized procedures. Individuals are strictly prohibited from using them on their own, as improper operation may lead to risks such as infection, uncontrollable bleeding, and tissue damage. The following only introduces the standard operating procedures for medical personnel to help understand their usage guidelines, rather than guiding individual operations:

1. Preparation before operation (core: sterility and safety)

Environment and item preparation

Ensure that the operating environment is clean and dry, and has undergone air disinfection (such as ultraviolet disinfection).

Prepare disposable blood lancets (check if the packaging is intact and within the validity period; do not use if the packaging is damaged or expired), blood collection tubes (select according to the testing items, such as blood routine tubes, biochemical tubes, etc., and affix patient information labels in advance), iodine/alcohol cotton balls, sterile dry cotton swabs, tourniquets, and special medical waste bins.

Medical staff are preparing

Strictly adhere to hand hygiene: Wash your hands with running water and soap, or use hand sanitizer to disinfect your hands, and wear disposable sterile gloves.

Check patient information: confirm the patient's name, age, gender, and testing items to avoid collecting the wrong sample.

Patient preparation

Inform the patient of the purpose of blood collection and the key points of cooperation (such as clenching and relaxing the fist), to alleviate their nervousness.

Selection of blood sampling site: Elbow veins (such as the median cubital vein and basilic vein) are preferred. If the veins in the elbow are not obvious, superficial veins in the dorsal hand, wrist, or other areas can be selected. For children or special patients, fingertip capillaries may be chosen (requiring a dedicated peripheral blood sampling needle).

Bind the tourniquet 5-10cm above the blood collection site (with a tightness suitable for inserting one finger, and the binding time should not exceed 1 minute to avoid tissue hypoxia), and have the patient repeatedly clench their fist to make the veins engorge.

II. Standard Operating Procedures (Taking Venous Blood Sampling as an Example)

Disinfect the blood collection site

Use iodophor or 75% alcohol cotton ball to wipe in a clockwise or counterclockwise spiral manner, with the blood collection point as the center. The disinfection range should have a diameter of ≥5cm. Allow the disinfectant to dry naturally (about 30 seconds). During this period, avoid touching the disinfected area to prevent contamination.

Blood sampling through puncture

The medical staff fixes the skin at the blood collection site with one hand (tightening the skin with the thumb to make the vein more visible), and holds the blood collection needle (usually a "pen-type blood collection needle" or "butterfly-wing type blood collection needle") with the other hand, with the bevel of the needle tip facing up, and pierces into the vein at an angle of 15°-30° to the skin.

After puncture, if blood is seen returning to the tail of the blood collection needle or inside the blood collection tube (indicating successful puncture), immediately loosen the tourniquet, ask the patient to unclench their fist, and insert the blood collection tube into the blood collection needle connector (vacuum blood collection tubes will automatically aspirate blood, without the need for squeezing). Collect a sufficient amount of blood according to the testing requirements (different blood collection tubes have different scales, such as approximately 2ml for blood routine tubes and approximately 5ml for biochemical tubes).

Needle removal and hemostasis

After blood collection is complete, first remove the blood collection tube, then quickly withdraw the blood collection needle, while simultaneously applying pressure to the puncture site with a sterile dry cotton swab (the pressure should be applied to the extent that there is no bleeding and the patient feels no significant pain, avoiding rubbing to prevent subcutaneous bruising). Have the patient maintain pressure for 3-5 minutes (for individuals with abnormal blood clotting, the duration should be extended to 10 minutes or more) until the bleeding stops.

III. Key precautions (safety red lines)

Single-use principle: Blood collection needles are disposable medical devices. They must be immediately placed in a dedicated sharps box for medical waste (protected against puncture and leakage) after use. Reuse or random disposal is strictly prohibited to avoid cross-infection (such as transmission of blood-borne infections like hepatitis B, hepatitis C, and AIDS).

Avoid accidental puncture: Medical staff need to concentrate when operating to avoid accidentally puncturing themselves or patients; if occupational exposure occurs (such as being pricked by a contaminated blood collection needle), they must immediately follow the procedures (squeezing out blood, disinfection, reporting, and testing).

Handling of special populations: For patients who are prone to fainting from blood or acupuncture needles, prior notification and preventive measures (such as lying down for blood collection and distracting their attention) should be taken. For children, elderly individuals, or those with poor vascular conditions, thinner blood collection needles should be selected, and the procedure should be performed gently to reduce pain.

In summary, the use of blood lancets involves strict medical standards and safety requirements, and individuals must not purchase and use them on their own. If blood collection is necessary (such as for physical examination or disease testing), it is imperative to visit a legitimate medical institution and have it performed by professional medical staff to ensure safety and sample accuracy.