Uses and Risks of Therapeutic Phlebotomy (2024)

Therapeutic phlebotomy is a medical procedure in which blood is removed from the body to treat certain blood disorders like polycythemia vera or hemochromatosis. It may be performed at a hospital or clinic.

The procedure reduces an excessively high number ofred blood cellsor excessively high levels of iron in the blood. Once these levels are normalized, the treatment may be given less frequently and sometimes stopped.

Although therapeutic phlebotomy is sometimes referred to as "blood-letting," it is done for highly specific reasons rather than the generalized use of the centuries-old practice thought to cure illnesses up until the late 19th century.

This article describes what conditions therapeutic phlebotomy treats, how it works, and what to expect during treatment.

Benefits of Therapeutic Phlebotomy

Phlebotomy is the medical practice of removing blood, mostly for blood tests or donations. Therapeutic phlebotomy, by contrast, is used to correct imbalances in your blood that cause illness. The goal is to restore blood levels to the expected values.

There are five conditions for which therapeutic phlebotomy is commonly used:

Polycythemia Vera (PV)

Polycythemia vera (PV) isa rare blood cancer that causes your bone marrow to produce too many red blood cells. This can cause your blood to thicken and clot excessively. The clotting, in turn, can lead to a heart attack and stroke.

Therapeutic PV can reduce the risk of these complications by decreasing the proportion of red blood cells in your blood, as measured by a hematocrit (HCT) blood test.

In adults with PV, 250 to 500 cubic centimeters (roughly 1 to 2 cups) of blood are removed daily or every other day until your HCT is between 0.4 and 0.45 (40% and 45%). Once normalized, your HCT will be retested every four to eight weeks.

Hereditary Hemochromatosis

Hereditary hemochromatosis is agenetic disorderthat causes the excess absorption of iron in your intestine from the foods you eat. This can lead to iron overload, causing damage to your brain, heart, liver, and pancreas as iron starts to accumulate.

Hereditary hemochromatosis is most common in people of Northern European ancestry, most especially those ofCelticdescent.

Therapeutic phlebotomy is a major part of the treatment, used to remove the excess iron before it can do any harm. A ferritin blood test measures blood iron levels in micrograms per liter of blood (μg/L ).

Therapeutic hemochromatosis is usually done once weekly or every two weeks until ferritin levels are 50 μg/L or less. Thereafter, ferritin levels are regularly monitored. The treatment can be repeated if necessary.

Acquired Hemochromatosis

Acquired hemochromatosis, also known as secondary hemochromatosis, is iron overload not caused by a genetic disease. Rather, it occurs as a result of another disease or a medical procedure that overloads the blood with iron.

Causes of secondary hemochromatosis include:

• Receiving multiple blood transfusions
• Thalassemia, sickle cell anemia, bone marrow failure, or other causes of severe anemia (usually after a blood transfusion is received)
• Alcoholic liver disease
• Kidney failure
• Taking too many iron supplements

The treatment for acquired hemochromatosis is largely the same as for hereditary hemochromatosis. Chelation therapy (using drugs that bind to iron and remove it from tissues) may also be used.

Porphyria Cutanea Tarda (PCT)

Porphyria cutanea tarda (PTC) is a rare blood disorder that causes your skin to blister when exposed to sunlight. PCT occurs when porphyrin—a chemical in your body that is transformed into hemoglobin—builds up in your blood.

About 20% of PCT cases are linked to genetic mutations. The remainder is caused by a deficiency of an enzyme called uroporphyrinogen decarboxylase (UROD) which transforms porphyrin into hemoglobin.

UROD deficiency can be caused by conditions like hemochromatosis, alcoholic liver disease, oral estrogen therapy, and exposure to aromatic hydrocarbons (created by the burning of coal, oil, gas, wood, garbage, and tobacco).

For PCT, therapeutic phlebotomy involves the removal of around 500 cubic centimeters (cc) of blood per day or every other day for a total of five to eight treatments. The aim is to reduce porphyrin to undetectable levels in blood and urine tests.

Kidney Transplant

Therapeutic phlebotomy may be used following a kidney transplant to treat a potentially serious complication known as post-transplant erythrocytosis (PTE). PTE occurs when HCT levels increase by more than 50% after the transplant.

PTE affects 10% to 15% of kidney recipients and usually develops eight to 24 months after the transplant. While HCT levels will normalize in 25% of people within two years, the other 75% may have persistently high counts which can increase the risk of organ rejection.

In cases like this, therapeutic phlebotomy is used to help prevent organ rejection. The procedure and goals are largely the same as for polycythemia vera, with the aim of reducing HCT to normal levels.

How Therapeutic Phlebotomy Is Done

Therapeutic phlebotomy can be performed at a blood donor center, physician's office, or a specialized apheresis unit at a hospital or dedicated facility.

Depending on how much blood is taken, the procedure can take an hour or less. Therapeutic phlebotomy is typically performed over several sessions. In between, blood tests are performed to see if levels have normalized.

Therapeutic phlebotomy may be performed daily or every other day for acute treatment. Maintenance treatments may be performed weekly, monthly, quarterly, or as needed depending on your blood results. Some cases, like acquired hemochromatosis, may not require follow-up treatments.

The procedure itself is more or less the same irrespective of the disease involved:

1. You will lie down on an examining table or sit back on a reclining chair.
2. The phlebotomist checks your pulse and blood pressure.
3. A needle is placed in a vein in your arm, which is connected to a tube and collection bag.
4. Between 250 and 500 cubic centimeters of blood is extracted.
5. The same amount of fluids is replaced either by mouth or into your vein.
6. Once enough blood is collected, the phlebotomist removes the needle and bandages the wound.
7. The blood is usually discarded.
   

Tips to Manage Therapeutic Phlebotomy

It is not uncommon after therapeutic phlebotomy to feel lightheaded or dizzy due to the loss of blood. Nausea, vomiting, and bruising are not uncommon.

To better manage the side effects of therapeutic phlebotomy, the phlebotomist will advise you to:

• Have someone drive you home.
• Avoid driving or using heavy machinery for at least 24 hours.
• Drink plenty of water.
• Avoid smoking for at least one hour.
• Avoid alcohol until you've at least had a full meal.
• Lie down if you are feeling dizzy or faint.

Call your healthcare provider immediately if you experience a high fever or the bleeding won't stop.

Summary

Therapeutic phlebotomy involves the removal of blood for blood to treat or manage conditions like polycythemia vera (PV), hereditary hemochromatosis, acquired hemochromatosis, porphyria cutanea tarda (PCT), and post-transplant erythrocytosis (PTE).

Blood is removed over several sessions when red blood cells or iron levels are dangerously high. The treatment will stop once levels are normalized, although maintenance treatments may be needed to keep the values within the expected range.