Therapeutic plasma exchange, commonly known as plasmapheresis, removes and replaces a person’s blood plasma. This treatment is used for conditions where the plasma contains harmful substances, such as autoantibodies or excess proteins. The process separates the liquid component of blood, discards it, and returns the blood cells with a replacement fluid. While plasmapheresis is generally safe and effective, understanding the potential side effects is important for patient preparedness and safety.
How the Procedure Leads to Side Effects
The process of plasmapheresis requires the temporary removal and return of a large volume of blood, which introduces two primary mechanisms for adverse reactions. First, the movement of blood causes dynamic fluid and volume shifts within the body. These rapid changes can disrupt the body’s internal balance and pressure regulation.
The second mechanism relates to the chemical agents required for the procedure, specifically the replacement fluids and anticoagulants. The apheresis machine requires an anticoagulant to prevent the blood from clotting within its tubing and filters. The most common anticoagulant used is citrate, which can affect the body’s electrolyte balance.
The choice of replacement fluid also influences the risk profile, as the discarded plasma must be substituted with a solution to maintain blood volume. Replacement fluids typically include saline, albumin solution, or Fresh Frozen Plasma (FFP). The body’s reaction to the infusion of these substances, coupled with the systemic effects of the anticoagulant, are the main sources of potential side effects.
Immediate and Expected Minor Reactions
Most adverse events experienced during or immediately following plasmapheresis are mild and easily managed by the medical team. One of the most common reactions is a drop in blood pressure, or hypotension, often due to the rapid shift in fluid volume or the effects of the anticoagulant. This may manifest as dizziness, lightheadedness, or faintness, and is often corrected by slowing the flow rate or administering intravenous fluids.
A frequent, specific reaction is known as citrate toxicity, caused by the calcium-binding properties of the anticoagulant. Citrate binds to ionized calcium, temporarily lowering available calcium levels, which can lead to symptoms like a tingling sensation (paresthesia) around the mouth or in the fingers and toes. Patients may also experience muscle cramps due to this temporary hypocalcemia, but these effects are quickly alleviated by slowing the citrate infusion or administering calcium supplements.
Other minor symptoms include nausea or vomiting, which can be related to fluid shifts or the vasovagal response. Patients may also feel cold or experience chills (hypothermia), typically resulting from the blood being cooled slightly as it circulates outside the body through the machine.
Rare But Serious Complications
While the procedure is generally safe, rare but serious complications can occur, requiring immediate medical attention. Allergic reactions, including severe anaphylaxis, are a risk primarily associated with the replacement fluid used. Replacement fluids like Fresh Frozen Plasma (FFP) carry a higher risk of triggering hypersensitivity reactions than albumin solutions, sometimes presenting as hives, itching (pruritus), or breathing difficulty.
The need for vascular access, particularly a central venous catheter, introduces risks such as localized infection or bleeding at the insertion site. Though infrequent, central line placement carries a small mechanical risk of complications like pneumothorax, where air enters the space between the lung and chest wall. The procedure can also temporarily affect the body’s clotting ability because the removed plasma contains clotting factors, which, combined with anticoagulants, slightly increases the risk of bleeding or blood clots forming.
Transfusion-Related Acute Lung Injury (TRALI) is a serious reaction to blood products that causes acute respiratory distress. Severe cardiovascular events, such as cardiac arrhythmias or shock, are also possible but occur in a very small percentage of procedures, often in patients with pre-existing heart conditions.
Monitoring and Managing Side Effects
The medical team employs a systematic approach to prevent and manage potential adverse events, beginning with pre-procedure screening to assess a patient’s stability and vascular access needs. Throughout the plasma exchange, trained personnel monitor the patient’s vital signs, including blood pressure, heart rate, and temperature, typically every 15 to 30 minutes.
If minor symptoms such as tingling or muscle cramps appear, the staff can quickly adjust the procedure rate or administer intravenous calcium to counteract the citrate effect. For a drop in blood pressure, treatment involves positioning the patient to encourage blood flow or infusing additional fluids. These interventions ensure that most reactions are resolved without stopping the procedure entirely.
After the session, patients are advised to remain well-hydrated and to watch for delayed symptoms. Patients should immediately report any signs of infection at the access site, such as redness, heat, or swelling, or more systemic issues like fever or persistent bleeding.