Phlebotomy is the practice of drawing blood from the circulatory system through an incision or puncture in the vein for sample analysis and diagnosis. It is done for the treatment of blood disorders of a patient. It is often performed to treat the condition named polycythemia vera that results in an increase in RBC volume. It is also prescribed to patients that display an increase of iron content in blood to fatal levels. Disorders with such symptoms include hepatitis B, hepatitis C, and hemochromatosis. Patients suffering from pulmonary edema may undergo phlebotomy to decrease their blood volume. This procedure is also used to remove blood from a person’s body during blood donation.
A health worker/physician or a nurse generally referred to as a phlebotomist usually performs phlebotomy. Blood is taken from a vein or below the elbow. Having said that, many tests require blood to be drawn from arteries. The area is wiped with antiseptic, followed by tying of an elastic band around the arm of the patient. The band makes the veins visible and helps retain blood within the arms. The phlebotomist selects the right vein, inserts a needle and detaches the elastic band. The required amount of blood is withdrawn, and the needle is drawn out of the vein. Simultaneously, the blood pressure and patient’s pulse is monitored during phlebotomy. Phlebotomists must collect blood in a certain order of draw to prevent contamination with other additives in different tubes.
Quantifying the blood drawn
Some tests only require the phlebotomists to make a small cut on the fingertips to draw a small amount of blood in a glass tube. The fingertip can be squeezed to get blood to surface. The amount of blood drawn solely depends on the purpose. Blood donors contribute around 500 ml of blood in a single session. Usually, one or several small tubes are used. Therapeutic phlebotomy requires more blood to be withdrawn than donations and analysis. For treatment of polycythemia vera, blood is drawn out in such a manner to leave only 45% of hematocrit.
Medical analysis post phlebotomy
Patients who are scheduled to undergo phlebotomy can be asked to stop all medications or to avoid fast food before the test. Patients will be asked about medical history, followed by an examination of blood pressure. Their hematocrit will be examined, before donation, with a finger stick test. Pressure needs to be placed on the site with cotton balls to avoid bleeding. A bandage has to be applied immediately after that. The patient may feel nauseous and therefore should be encouraged by phlebotomist to take rest for a sometime after the completion of the procedure. Patients need to drink fluids and eat regularly over the span of the next 24 hours.
Need for serious medical attention
Patients who experience profuse bleeding or swelling of the injected site, post phlebotomy should be given immediate medical attention. Besides being at risk of infection, therapeutic phlebotomy may lead to anemia and thrombocytosis in some patients. The chance of infection can be decreased by the use of sterilized needles and equipment, followed by serious attention to the right techniques.