What are the indications for phlebotomy (blood draw)?

From the Guidelines

Phlebotomy is indicated for therapeutic purposes, such as treating conditions with excess red blood cells or iron, including hemochromatosis, polycythemia vera, and porphyria cutanea tarda, as well as for diagnostic testing and blood donation. The indications for phlebotomy can be broken down into several categories, including:

• Therapeutic phlebotomy, which is used to treat conditions with excess red blood cells or iron, such as hemochromatosis, polycythemia vera, and porphyria cutanea tarda, typically removing 450-500mL of blood at intervals determined by the condition's severity and patient response 1.
• Diagnostic phlebotomy, which includes routine health screenings, disease monitoring, pre-surgical evaluations, and emergency assessments to measure parameters like complete blood counts, metabolic panels, coagulation studies, and specific biomarkers.
• Blood donation for transfusion, which typically involves collecting 450-500mL of blood.

For hemochromatosis, weekly phlebotomy may be performed until ferritin levels normalize, then maintenance draws every 2-4 months 1. Special considerations include ensuring proper patient identification, using appropriate collection tubes for specific tests, maintaining sterile technique, and considering patient factors like age, weight, and medical conditions that might contraindicate phlebotomy. The procedure works by directly removing excess cells or iron in therapeutic cases, while diagnostic draws provide samples that reveal critical information about a patient's health status through laboratory analysis.

In patients with hemochromatosis, phlebotomy has been shown to improve survival, reduce tissue iron stores, and improve sense of well-being, energy level, and cardiac function 1. Additionally, phlebotomy can help reduce the risk of hemochromatosis-related complications, such as liver disease, diabetes, and heart problems 1.

It is essential to note that phlebotomy should be performed under the guidance of a healthcare professional, and the frequency and volume of blood removal should be individualized based on the patient's condition and response to treatment 1.

From the Research

Indications for Phlebotomy

The indications for phlebotomy, or blood draw, can be categorized into several areas based on the provided evidence:

• Therapeutic Phlebotomy: This is indicated for the treatment of various blood disorders, including:
  • Hemochromatosis 2
  • Polycythemia vera 2, 3
  • Porphyria cutanea tarda 2
  • Sickle cell disease 2
  • Nonalcoholic fatty liver disease with hyperferritinemia 2
• Management of Iron Overload: Phlebotomy is used to reduce iron levels in patients with hemochromatosis-associated iron overload 4 and to manage microcytic polycythemia due to chronic hypoxia 5.
• Metabolic Syndrome: Phlebotomy-induced reduction of body iron stores has been shown to lower blood pressure and improve markers of cardiovascular risk and glycemic control in patients with metabolic syndrome 6.
• Polycythemia Vera: Therapeutic phlebotomy is used to normalize hematocrit levels and reduce the incidence of thrombotic complications in patients with polycythemia vera 3.

Key Considerations

When considering phlebotomy, it's essential to evaluate the patient's specific condition and the potential benefits and risks of the procedure. For example, in patients with polycythemia vera, phlebotomy can exacerbate iron deficiency, contributing to non-hematological symptoms 3. In contrast, phlebotomy has been shown to have beneficial effects on blood donors with metabolic syndrome 6.