Therapeutic Phlebotomy: What Is It and When Is This Treatment Recommended?
A therapeutic phlebotomy is a procedure in which a considerable amount of blood is extracted in order to improve the clinical conditions of patients. This technique, also known as “bloodletting”, was frequently practiced in ancient times. The multiple indications in which it was used responded more to the beliefs of the time than to effective treatment of diseases.
In fact, many of these procedures caused more harm than good. Thus, with the advent of science and a better understanding of the pathophysiological phenomena involved, bloodletting gradually fell into disuse, being replaced by treatments more consistent with the origin of the disease. However, there are still some instances in which a phlebotomy remains a useful tool.
What is a therapeutic phlebotomy?
The procedure consists of puncturing a peripheral vein (usually of the forearm) with an extraction device, which has a needle and is connected to a 500 ml collection bag.
It’s important to note that the volume extracted depends on the therapeutic purpose of the bleeding and on the age and clinical conditions of the patient. Thanks to the help of a blood donation scale, it’s possible to monitor the volume being obtained in real-time.
The procedure lasts between 20 and 40 minutes in total and is performed with the patient in a semi-sitting position. On the other hand, the location of the collection bag should be below the level of the arm during the procedure to allow the extraction of blood by gravity.
The patient who will undergo therapeutic phlebotomy should be assessed prior to the procedure, with a record of vital signs and a pertinent explanation of the procedure. It’s important to be well hydrated and to have eaten well. After the procedure, the patient should drink enough fluids and avoid sudden changes in position.
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When is a therapeutic phlebotomy used?
For centuries, bloodletting was a common procedure to treat various conditions. Although the technique was rudimentary, the purpose was to draw enough blood to remove the cause of the disease, which was believed to be there.
Despite its former overuse, there are few clinical conditions in which a phlebotomy is a form of therapy today. Even so, its practice continues to have major detractors.
Hereditary hemochromatosis (HH) is a congenital disorder with autosomal recessive inheritance, which is the most common genetic disorder of metabolism.
In these patients, there is an increased uptake of iron from the diet, causing the metal to accumulate progressively in the body. The clinical manifestations vary greatly among patients and there are even cases in which no symptoms appear.
Treatment is based on the gradual reduction of iron deposits and the consequent maintenance of adequate iron values, since the excess metal damages various organs in the body, especially the liver, heart, and pancreas.
This is why this is one of the conditions in which a therapeutic phlebotomy is still valid today. In fact, early treatment prevents progression to liver cirrhosis and improves the survival of these patients.
In the initial phases, the frequency of bleeding varies between 1 and 2 weeks, depending on the individual’s condition and tolerance to the technique. Likewise, the duration of treatment ranges from six months to two years.
After achieving normal values, the case is followed up periodically and the need to establish maintenance therapeutic guidelines in which phlebotomies are distanced in time is evaluated.
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The contraindications of bleeding in patients with HH
Not all patients are suitable for this treatment, so there are also other treatment options. In some cases, where none of these treatments can be implemented, the use of iron chelators can be resorted to. However, these have not shown good effectiveness. Therapeutic phlebotomy is contraindicated in the following situations:
- Coronary heart disease
- Congestive heart failure
- Advanced age
A therapeutic phlebotomy for Porphyria cutanea tarda
Another condition in which iron accumulation in the body may be associated is Porphyria cutanea tarda. In this disorder, a liver enzyme responsible for degrading porphyrins is affected, so these molecules are increased in these patients.
The main clinical manifestations include the appearance of lesions on exposed areas of the skin (photosensitivity) and varying degrees of liver function impairment.
In these patients, repeated phlebotomies are a first choice treatment, aimed at lowering their iron levels. The reason is that, in addition to the fact that the excess metal causes organ damage, it also leads to liver enzyme inhibition. Therefore, by reducing these deposits, the enzyme would be released, with the consequent reduction of accumulated porphyrins.
Treatment guidelines for Porphyria cutanea tarda
The indication for treatment with bloodletting should be individualized with periodic controls of hemacytometric indices. In general terms, the extractions are spaced over time until acceptable values are achieved.
However, due to the tendency to recur, it’s necessary for the doctor to evaluate the need for maintenance treatments. In these patients, the use of antimalarials in combination with bloodletting is common.
Various congenital heart diseases lead to an increase in pulmonary vascular resistance, with the consequent appearance of pulmonary hypertension. In the most severe cases, Eisenmenger’s syndrome develops.
In this syndrome, there’s an obstruction to blood flow in the capillaries of the lungs due to various pathological mechanisms, hindering oxygen exchange and triggering the presence of hypoxemia.
The result is that the body tries to compensate for this deficit with increased production of erythrocytes, since they are responsible for carrying oxygen to the various cells of the body. However, as more erythrocytes circulate in the bloodstream, the proportion of the blood’s formative elements (hematocrit) increases, leading to an increase in its viscosity.
This reduced fluidity triggers symptoms grouped under the term hyperviscosity syndrome, which can be alleviated by performing a therapeutic phlebotomy.
However, unlike in hemochromatosis, in the case of Eisenmenger syndrome, this technique does not constitute a definitive treatment. Moreover, its application leads to a decrease in iron deposits and, therefore, should be considered with caution in each patient.
Chronic pneumopathies and therapeutic phlebotomy
Similarly, various pulmonary conditions lead to chronic hypoxia and increased erythrocyte production, with the consequent development of hyperviscosity syndrome.
Because of this, a phlebotomy can be considered an option to treat symptoms and improve patients’ conditions. However, the studies reviewed do not allow for long-term follow-up, making the benefit of the technique questionable.
The controversy of therapeutic phlebotomy
Some authors call fora reflection on the systematic discarding of blood collected from patients with hemochromatosis in many countries. It has been shown that the quality of blood derived from these patients is equal to or higher than that of regular blood bank donors. Furthermore, they believe that the discarding of these units is an invaluable waste, since bleeding is usually performed periodically.
Similarly, they allude that the only justification for not allowing the use of these components is that it does not constitute in essence an altruistic donation because the patient obtains a health benefit by undergoing a therapeutic phlebotomy.
However, they warn that after blood collection, the decision to donate or not should be considered. Therefore, they emphasize that it’s necessary to evaluate this possibility. These same authors clarify since it is a genetic disorder, hereditary hemochromatosis is not transmitted by such a transfusion.It might interest you...