Therapeutic Phlebotomy Explained
Phlebotomy is primarily a process of collecting blood samples for testing and other purposes. In certain situations, it is also used as a means of treatment. Therapeutic bleeding, as therapeutic phlebotomy is sometimes called, may be indicated for a wide range of health conditions, including:
- Hemochromatosis
- Polycythemia vera (PV)
- Porphyria cutanea tarda
- Polycythemia secondary to arterio-venous fistulae
- Cyanotic congenital heart disease or cor pulmonale
- Sickle cell crisis
There are also instances when it is ordered even if a patient is not showing any form of symptoms. Based on the Hemochromatosis Management Working Group (Barton et al, 1998) guidelines, phlebotomy must be initiated under these circumstances:
- Men with 300 ug/L serum ferritin levels or more
- Women with 200 ug/L serum ferritin levels or more
Therapeutic phlebotomy for hemochromatosis patients
Hemochromatosis is a disease that can be simply referred to as an iron overload. Although the body needs iron, too much of it can spell bad news. If left untreated, it can cause excess build up in the heart, liver, joints, pancreas and pituitary that can be fatal. It also increases the risk of arthritis (osteoarthritis, osteoporosis), cirrhosis of the liver or liver cancer, diabetes mellitus, depression, gall bladder disease, hypothyroidism, hypogonadism, irregular heart beat or heart attack, impotence, infertility and some cancers. Since this disease is genetic, test for iron stores must be performed. If there is an excess, therapeutic phlebotomy must be carried out.
Benefits of therapeutic bleeding
- Prevent complications caused by iron overload when done in patients that are still not showing any symptoms, but are susceptible to hemochromatosis. Early treatment promotes normal life expectancy.
- Results in resolution or marked improvement for patients experiencing weakness, fatigue or lethargy related to iron.
- Results in resolution or marked improvement for patients showing elevated concentration of serum of hepatic enzymes.
- Promotes cessation of iron-related diarrhea.
- Results in resolution when therapeutic phlebotomy is performed on patients with hepatomegaly.
- For patients with hepatic cirrhosis, it can slow the progression of liver failure.
- Results in resolution or marked improvement for patients experiencing right-upper quadrant pain.
- For patients with arthropathy, it can lead to improvement in arthralgias and change in deformity of joints.
- If diabetes mellitus is iron related, therapeutic bleeding can lead to occasional improvement.
It can also help in patients with hyperthyroidism or hypothyroidism, cardiomyopathy, hyperpigmentation, hyperferritinemia, and hyperferremia, although resolutions may vary.
Therapeutic phlebotomy for polycythaemia patients
Also called erythrocytosis, polycythaemia happens when there is an increase in the red blood cell mass. It is comes in two types: absolute polycythaemia or relative polycythaemia that are defined as increase in the number of red blood cells and decrease in the plasma volume, respectively. People suspected with polycythaemia can fall under the following criteria:
- Increase in haematocrit, more than 52% in men or 48% in women
- More than 18.5 g/dL increase in haemoglobin level in men and 16.5 g/dL increase in women
- Increase in red blood cell count
Absolute polycythaemia explained
Absolute polycythaemia is divided into primary and secondary polycythaemias. The former includes polycythaemia vera (PV) that happens with an increase in red cell mass or in white blood cell and platelet counts. The Polycythaemia Vera Study Group (PVSG) and World Health Organisation (WHO) have provided diagnostic criteria for PV (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3934278/table/tI-blt-12-s75/), which varies with regards to how PV is diagnosed.
PV may also be suspected among the following patients:
- More than 18 g/dL elevated haemoglobin level in men and more than 16 g/dL in women
- More than 52% haematocrit in men and more than 47% in women
- Splenomegaly with or without leucocytosis and thrombocytosis
- Presenting with portal venous thrombosis
Secondary polycythaemia, on the other hand, happens when there is an increase in the erythropoietin level. There are many causes of secondary polycythaemia (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3934278/table/tII-blt-12-s75/), but not everyone may be indicated for therapeutic phlebotomy.
Relative polycythaemia explained
The decrease in plasma volume that causes an increase in the mass of red blood cells characterizes relative polycythaemia. It is also indicative of any condition that causes fluid loss, such as severe burns and dehydration. Patients suffering with this type of relative polycythaemia will not be treated through therapeutic bleeding.
Other indications for therapeutic phlebotomy bleeding
The procedure can decrease the number of days that patients with sickle cell disease spend in the hospital due to painful crises. This is according to a study carried out on seven children. This is because phlebotomy reduces hemoglobin level and decreases the viscosity of blood. This, in turn, reduces HbS molecule polymerisation in sickle cell disease. Whether used alone of in conjuction with hydroxyurea, therapeutic bleeding can help.
Phlebotomy used to be considered treatment for chronic hepatitis C. This is because patients suffering with this condition have difficulty eliminating iron from their bodies, resulting in iron toxicity. In 2006, however, the American Gastroenterological Association ruled it out as treatment of chronic hepatitis C.
It was also considered a component for treating Alzheimer’s disease since iron load may have a role to play in the pathogenesis and progression of the disease. But this is still in theory and more trials are still needed.
What exactly happens during phlebotomy treatment?
In therapeutic bleeding, about 500 ml of blood is removed using a large-bore needle for over 15 to 30 minutes. This process stimulates the bone marrow to make new red blood cells (RBC). During the course of new RBC production, iron stores are depleted that results in the drop of iron to a safe and healthy level. To reach normalization, phlebotomy must be carried out weekly until mild hypoferritinemia occurs even on just one occasion or when serum ferritin level is 10 to 20 ug/L.
Customized therapeutic phlebotomy
It is vital that clinicians design individualized phlebotomy treatment. Apart from the type of condition the patient is suffering from, other factors must be considered, including the age, gender, general health, likelihood of compliance and weight. It is also important that before treatment is carried out, checks must be done on a patient’s diagnosis, baseline ferritin, hematocrit, hemoglobin and therapeutic end points.
Bottom line
Phlebotomy is a safe and cost-effective treatment for various diseases, particularly those related with iron overload. Whether used as the only treatment or adjunctive therapy, it can provide relief from many disorders.
