2. Mannikins

2.6. Venepuncture

 You are Emergency FY-2 doctor where you see Mr Robert Williams, who is 49 year old gentleman. He is brought by ambulance with c/o taking drug overdose. He is in major Bay-8 and you are ready to see the next patient. Please go to Mr Young Lo, talk to him, discuss the management with him and perform the necessary blood investigations.

Venepuncture Technique

Venepuncture is the process of drawing blood from a vein for diagnostic, therapeutic, or monitoring purposes. The steps involved in venepuncture are as follows:

  1. Preparation: The healthcare professional should obtain informed consent from the patient and explain the procedure. They should also prepare the necessary equipment, such as gloves, tourniquet, alcohol swabs, and needles.

  2. Patient positioning: The patient should be seated or lying down, with their arm extended and supported.

  3. Tourniquet application: A tourniquet is wrapped around the patient's upper arm to increase the pressure in the veins and make them easier to locate.

  4. Site selection: A suitable vein is selected, usually in the antecubital fossa (the bend of the elbow).

  5. Skin preparation: The skin over the selected vein is cleaned with an antiseptic solution to reduce the risk of infection. The skin should be ideally cleaned for 30 seconds moving from centre outwards and should be left to air dry for 30 seconds.

  6. Needle insertion: The needle is inserted into the vein at a 15 to 30-degree angle, with the bevel facing upward. The healthcare professional should look for a flashback of blood to confirm that the needle is in the vein.

  7. Collection of blood: Once the needle is in the vein, the healthcare professional should remove the tourniquet and collect the required amount of blood using a syringe or collection tube.

  8. Needle removal: Once the blood has been collected, the healthcare professional should remove the needle and apply pressure to the site with a cotton ball or gauze to stop bleeding.

  9. Post-procedure care: The healthcare professional should dispose of the used equipment properly, label the blood samples, and provide appropriate care to the patient, such as applying a bandage to the site and monitoring them for any adverse reactions.

It is important for healthcare professionals to follow proper venepuncture techniques to minimize the risk of complications and ensure accurate test results.

Different color codes of blood collection bottles

There are different color codes for blood collection bottles, and each color represents the type of additive or the type of test for which the blood sample is collected. The following are the most common color codes for blood collection bottles:

  1. Red: This bottle contains no additive and is used for collecting serum samples for chemistry tests, such as liver function tests, lipid profile, and glucose tests.

  2. Yellow: This bottle contains an additive called SPS (sodium polyanetholesulfonate) and is used for collecting blood for blood cultures.

  3. Light Blue: This bottle contains an additive called sodium citrate and is used for collecting plasma samples for coagulation studies, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT).

  4. Green: This bottle contains an additive called heparin and is used for collecting plasma samples for chemistry tests, such as electrolytes and renal function tests.

  5. Lavender or Purple: This bottle contains an additive called EDTA (ethylenediaminetetraacetic acid) and is used for collecting whole blood or plasma samples for hematology tests, such as complete blood count (CBC) and blood typing.

  6. Gray: This bottle contains an additive called sodium fluoride and potassium oxalate and is used for collecting blood for glucose and lactate tests.

It is important to note that the color codes may vary between different institutions or countries, and it is always recommended to check the label on the collection bottle to confirm the type of additive or test for which the bottle is intended.

Tags: