Therapeutic Plasma Exchange (TPE), often referred to as plasmapheresis, is a procedure that cleanses the blood by removing harmful substances from the plasma. The process involves drawing the patient’s blood, separating the liquid plasma from cellular components, and discarding the plasma. The blood cells are then recombined with a replacement fluid, such as albumin or donor plasma, and returned to the patient. TPE is used to treat various conditions, including autoimmune disorders and certain hematologic diseases, by removing disease-causing agents like autoantibodies or abnormal proteins. As TPE is an invasive medical intervention, understanding its safety profile and potential risks is essential.
Common Physical Side Effects of the Procedure
The most frequently reported side effects of Therapeutic Plasma Exchange are generally mild and temporary, often relating to the physical mechanics of the process. Vascular access issues are common, including localized discomfort, bruising, or the formation of a small hematoma at the needle insertion site. Patients may also experience a tingling sensation around the mouth or in the fingers and toes, known as paresthesia, which is often the first sign of a mild electrolyte shift.
Temporary drops in blood pressure, or hypotension, can occur due to the rapid shift in fluid volume as plasma is removed and replaced. This volume change can cause transient symptoms such as dizziness, lightheadedness, or mild nausea. A drop in blood pressure was reported in up to 6% of treatments in some studies. Patients also commonly report feeling cold during the procedure or experiencing fatigue afterward that can last for the remainder of the day.
Mild allergic reactions are also relatively frequent, most commonly presenting as a rash, pruritus (itching), or urticaria (hives). These reactions are typically a response to the replacement fluid, especially when donor Fresh Frozen Plasma (FFP) is used. Pruritus and urticaria have been documented in up to 7% of treatments in some patient populations.
Potential for Severe Systemic Complications
While most adverse events are mild, TPE does carry the potential for severe, systemic complications that require immediate medical intervention. One of the most significant physiological risks is citrate toxicity, which occurs because citrate is added to the blood circuit as an anticoagulant to prevent clotting in the machine. Citrate binds with calcium in the patient’s bloodstream, potentially leading to hypocalcemia, or dangerously low calcium levels.
Symptoms of citrate toxicity range from the mild tingling already mentioned to more severe manifestations like muscle spasms, cramps, and, in rare instances, cardiac rhythm disturbances. The risk of severe, potentially life-threatening adverse reactions is low, occurring in approximately 0.12% of procedures.
Severe allergic reactions, including anaphylaxis, represent another serious, though rare, complication, particularly when Fresh Frozen Plasma is used as the replacement fluid. These reactions involve a systemic immune response and can progress rapidly to cause wheezing, difficulty breathing, or severe hypotension. The use of replacement fluids also introduces a small risk of blood product transmission, including viruses or pathogens.
The procedure can also temporarily affect the body’s natural clotting mechanisms, leading to an increased risk of bleeding or, conversely, clotting. Plasma removal depletes coagulation factors, and this temporary depletion can elevate the risk of hemorrhage. The need for central venous access—a catheter placed in a large vein—to facilitate high blood flow rates introduces the separate risks of infection and local thrombosis (clotting) at the catheter site. Infection at the central line site is a concern, as the underlying conditions treated by TPE often involve some degree of immunosuppression.
Protocols for Minimizing and Managing Risk
The safety of Therapeutic Plasma Exchange relies heavily on strict protocols executed by specialized medical teams. Before the procedure begins, a thorough pre-procedure screening is performed, which includes reviewing the patient’s medical history and current medications. Baseline blood work, specifically checking serum calcium levels, is routinely conducted to establish a reference point and anticipate the potential for citrate toxicity.
During the exchange process, the patient is under continuous monitoring by trained apheresis nurses and physicians. Constant checks of vital signs, including heart rate, blood pressure, and oxygen saturation, ensure that any hemodynamic instability is detected immediately. This monitoring allows for prompt adjustments to the fluid removal rate or the administration of stabilizing fluids.
To proactively manage the most common severe risk, protocols mandate the readiness to administer intravenous calcium gluconate. This is infused if a patient shows signs of hypocalcemia or is at a high risk for it, directly counteracting the calcium-binding effect of the citrate anticoagulant. Similarly, all facilities must have a standing protocol and readily available medications, such as epinephrine and antihistamines, to quickly manage and reverse any severe allergic or anaphylactic reactions.
For patients requiring repeated treatments, the choice of vascular access is carefully considered. Peripheral veins are used whenever possible to minimize the infection and clotting risks associated with central venous catheters. If a central line is necessary, strict sterile techniques are followed during placement and maintenance.