Phlebotomy consists of placing a catheter in a blood vessel, with the aim of administering medication to patients with difficult venous access or to monitor central venous pressure, or even to bleed, which is an old medical practice performed with the aim of decrease iron stores or the number of red blood cells, as in cases of hemochromatosis or polycythemia vera.
Currently, the term phlebotomy is more associated with blood collection for laboratory tests and donation. Phlebotomy is a delicate procedure and must be performed by a professional properly trained for this function, such as a nurse, as any error in the collection can alter the results of the exams.
When is indicated
Phlebotomy is most used for the purpose of diagnosis, with the collected blood sent to the laboratory for analysis to be carried out in order to assist the diagnosis and monitoring of the patient. Phlebotomy corresponds to the first stage of diagnosis, and must be performed by a nurse, or another trained professional, to avoid changes in the results.
In addition to being essential for carrying out laboratory tests for diagnosis and monitoring of the patient, phlebotomy can be performed as a therapy option, being then called bleeding. Bleeding aims to solve problems related to the increased number of red blood cells, in the case of polycythemia vera, or a large accumulation of iron in the blood, which is what happens in hemochromatosis. Understand what hemochromatosis is and how to identify symptoms.
Phlebotomy is also an essential part of the blood donation process, which aims to collect approximately 450 mL of blood, which goes through a series of processes until it can be used by a person in need, helping with their treatment. Find out how blood transfusion is done.
How phlebotomy is done
The collection of blood from phlebotomy can be done in hospitals and laboratories and fasting depends on the type of test that was requested by the doctor. See which fasting times are most common for blood tests.
The collection can be done with a syringe, in which a total amount of blood is removed and then distributed in the tubes, or in a vacuum, which is more common, in which several tubes of blood are collected in a pre-established order.
Then, the health professional should follow the following step-by-step:
- Gather all the necessary equipment for collection, such as the tube in which the blood will be stored, gloves, withers, cotton or gauze, alcohol, needle or syringe. Check the patient's data and identify the tubes in which the collection will be performed; Place the person's arm under a clean sheet of paper or towel; Locate a good-sized vein that is visible, straight and clear. It is important that the vein is visible without applying the tourniquet; Place the tourniquet 4 to 5 fingers above the collection site and re-examine the vein; Put on the gloves and disinfect the place where the needle will be placed. Disinfection should be done with 70% alcohol, using a cotton circular motion. After disinfection, you should not touch the area or run your finger over the vein. If this happens, a new disinfection is necessary; Insert the needle into the arm and collect the necessary blood for the vials.
Finally, the needle should be removed gently and then a light pressure should be applied to the collection site with clean gauze or cotton.
In the case of the collection performed in babies, blood is usually drawn through a prick in the heel or, more rarely, in the earlobe.
