Polycythemia is a blood disorder characterized by the overproduction of red blood cells, which causes the blood to become abnormally thick. This condition increases the blood’s viscosity and slows circulation, significantly raising the risk of severe complications like blood clots, stroke, and heart attack.
Therapeutic phlebotomy, a process of controlled blood removal, is the most common and immediate treatment method used to manage this dangerous increase in red blood cell count. This procedure is designed to reduce the volume of excess cells and mitigate the associated life-threatening vascular risks.
Defining Therapeutic Phlebotomy and Its Goal
Therapeutic phlebotomy is a medical procedure that involves withdrawing a specific amount of blood from the body, closely resembling a standard blood donation. This treatment decreases the overall red blood cell mass in the circulatory system, directly addressing the underlying issue of blood thickening. By removing blood, the procedure lowers the proportion of red blood cells to total blood volume, a measurement known as the hematocrit (HCT) level.
The goal of this intervention is to maintain the patient’s hematocrit below a specific target, typically less than 45%. Keeping the HCT level within this range significantly reduces the likelihood of major thrombotic events, such as deep vein thrombosis or pulmonary embolism. The reduction in red cell mass effectively lowers the blood’s viscosity, allowing it to flow more smoothly through the vessels and relieving symptoms like headaches, dizziness, and visual disturbances.
The Phlebotomy Procedure
Preparation for a therapeutic phlebotomy session focuses mainly on adequate hydration to help stabilize blood volume during the procedure. The procedure is usually conducted in a clinic, hospital, or specialized infusion center by a trained professional. The technician inserts a sterile needle into a vein, typically in the arm, and the blood flows through tubing into a collection bag.
The standard volume of blood removed during a single session is approximately one unit, ranging from 450 to 500 milliliters. For elderly patients or those with pre-existing heart conditions, a smaller volume (250 to 300 milliliters) may be removed to reduce the risk of adverse reactions. The actual blood draw usually takes between 10 and 30 minutes, with the entire appointment, including preparation and observation, lasting about 30 to 60 minutes. After the needle is removed, the site is bandaged, and patients are advised to rest briefly while drinking fluids to aid in plasma volume replenishment.
Managing Treatment and Side Effects
The treatment schedule is divided into two phases: an aggressive induction phase and a less frequent maintenance phase. Initially, phlebotomy may be required weekly or twice weekly to rapidly bring the elevated hematocrit down to the target level below 45%. Once this goal is achieved, the frequency is reduced to a maintenance schedule tailored to the individual patient’s needs, often occurring every two to three months.
Treatment success is monitored by regular complete blood count tests to check the hematocrit level before each scheduled session. This testing determines when the next phlebotomy is necessary, ensuring the HCT remains within the therapeutic range. Patients commonly experience immediate side effects following the procedure, such as mild fatigue, lightheadedness, or dizziness, which usually resolve quickly with rest and hydration.
A common long-term consequence of repeated phlebotomy is the development of iron deficiency, as the body uses iron to create new red blood cells to replace those removed. Although iron deficiency can cause symptoms like tiredness and weakness, it is often a desirable outcome in polycythemia management because it naturally slows the production of new red blood cells. In cases where patients require very frequent phlebotomies, a physician may introduce a cytoreductive medication to help reduce cellular overproduction and lessen the overall burden of treatment.