Understanding Therapeutic Plasma Exchange (TPE)
Therapeutic Plasma Exchange (TPE), also known as plasmapheresis, is a procedure that removes and replaces the liquid portion of the blood, called plasma. In certain diseases, the plasma contains harmful components, such as autoantibodies that attack the body's own tissues. By removing this plasma and replacing it with a substitute fluid like albumin, saline, or fresh frozen plasma (FFP), the treatment aims to reduce the concentration of these harmful substances.
Common and Mild Side Effects
Most side effects of plasma exchange are mild, temporary, and easily managed by the medical staff overseeing the procedure. These typically include:
- Fatigue and Weakness: Many patients report feeling very tired or fatigued after a session, a normal reaction as the body adjusts to the fluid changes. It is recommended to rest and avoid strenuous activity immediately after treatment.
- Hypotension (Low Blood Pressure): The rapid fluid shift can cause a temporary drop in blood pressure, leading to dizziness, lightheadedness, or nausea. Nurses monitor blood pressure throughout the procedure and can adjust the machine's speed or administer fluids to stabilize it.
- Paresthesias (Tingling Sensation): This is one of the most common reactions, caused by the anticoagulant citrate, which is used to prevent the blood from clotting in the machine. The citrate can temporarily lower calcium levels in the blood, leading to a tingling or numbness in the lips, fingers, or toes. This is quickly reversed by giving calcium supplements orally or intravenously.
- Feeling Cold: Because the blood is cycled out of the body and back in, some patients feel cold during the procedure. Hospitals use warming blankets and fluid warmers to help keep patients comfortable.
- Nausea and Vomiting: A feeling of nausea can accompany the drop in blood pressure. It is typically mild and can be managed with anti-nausea medication if necessary.
Moderate to Severe Risks and Complications
While much less common, more severe complications can occur, especially in critically ill patients.
- Allergic Reactions: Some patients can have an allergic reaction to the replacement fluid, particularly fresh frozen plasma (FFP). Symptoms include hives, itching, rash, or fever. These reactions are treated with medication like antihistamines.
- Infection: Any procedure requiring vascular access, especially a central venous catheter, carries a risk of infection at the access site. Additionally, the removal of plasma, which contains antibodies and complement proteins, can temporarily suppress the immune system, potentially increasing the risk of infection, especially in patients who are already immunosuppressed.
- Bleeding Issues: As plasma contains clotting factors, their removal can increase the risk of bleeding or bruising. This is carefully monitored, and in cases of significant depletion, fresh frozen plasma containing clotting factors may be used as the replacement fluid.
- Electrolyte Imbalances: Beyond hypocalcemia, other electrolyte disturbances, such as hypomagnesemia, can occur. These are monitored with blood tests and corrected with supplements as needed.
- Heart and Lung Complications: In very rare instances, severe hypotension or electrolyte disturbances can affect heart rhythm, and in extremely rare cases, lead to cardiac arrest. A specific risk associated with FFP is Transfusion-Related Acute Lung Injury (TRALI), which can cause acute respiratory distress.
- Vascular Access Complications: Issues like blood clots, damage to blood vessels, or hematoma at the insertion site can occur, though skilled staff minimize these risks.
Factors Influencing Side Effects
Several factors can influence the type and severity of side effects a patient experiences:
- Replacement Fluid: The choice of replacement fluid is a significant factor. Albumin-saline is generally associated with fewer allergic reactions compared to fresh frozen plasma.
- Patient's Condition: A patient's underlying health, especially if they are critically ill or have specific pre-existing conditions, can impact the risk profile of the procedure.
- Vascular Access: The type of vascular access used, whether a peripheral IV in the arm or a central line in a larger vein, affects the risk of local complications like infection or bleeding.
A Comparison of Common Plasma Exchange Side Effects
| Side Effect | Description | Management | Prevention |
|---|---|---|---|
| Fatigue | General tiredness or exhaustion after the procedure, often lasting for several hours. | Rest and rehydration are key to recovery. | Ensure adequate rest both before and after the session. |
| Hypotension | A temporary drop in blood pressure leading to dizziness or lightheadedness. | Medical staff can slow the exchange or administer IV fluids. | Monitoring blood pressure closely and adjusting machine speed. |
| Paresthesias | Tingling in the lips, fingers, and toes caused by low blood calcium. | Oral or intravenous calcium supplementation is provided. | Calcium levels are monitored, and preventative supplements may be given. |
| Nausea | Feeling sick during or after the treatment. | Anti-nausea medications and slowing the exchange rate can help. | Informing staff immediately when symptoms begin. |
| Allergic Reaction | Hives, itching, or fever, usually mild but potentially more severe. | Antihistamines or other medications are administered. | Careful selection of replacement fluid (e.g., albumin over FFP). |
Conclusion
Plasma exchange is a safe and effective treatment for many conditions, and most patients tolerate it well. The most common side effects are mild and manageable with the close supervision of a trained medical team. While the risk of serious complications exists, it is rare. For most patients requiring this therapy, the benefits of removing disease-causing components from the blood far outweigh the risks. Always discuss any concerns about potential side effects with your healthcare provider before undergoing the procedure. For more information, you can read about the procedure on the American College of Rheumatology website.
