Plasma Exchange Protocol
The standard plasma exchange protocol involves exchanging 1-2 plasma volumes (calculated as body weight in kg × 0.045 L or 45 mL/kg) per session, with treatment frequency and total number of sessions varying by indication: 5-7 sessions on alternate days for severe neurologic conditions, 7-10 treatments for ANCA vasculitis with severe renal disease, and daily exchanges for 5-14 days in thrombotic thrombocytopenic purpura. 1, 2, 3
Volume Calculation and Replacement
Plasma volume is calculated using body weight (kg) × 0.045 L (or 45 mL/kg), which represents the standard one plasma volume. 1 Most protocols exchange 1-2 plasma volumes per session, though specific high-risk conditions may require larger volumes. 1
- For ANCA-associated vasculitis with severe renal disease, use 60 mL/kg volume replacement (approximately 1.3 times standard plasma volume), representing a high-volume protocol. 1
- For cardiac transplant antibody-mediated rejection, exchange 1-2 plasma volumes using the standard 45 mL/kg calculation. 1
- For hyperviscosity syndrome (multiple myeloma, Waldenström's), replace approximately two-thirds of plasma volume, typically 3-4 liters in adults. 1
Replacement fluids consist primarily of 5% albumin solution for most indications, though fresh-frozen plasma may be used when coagulation factors need replacement. 1, 3
Disease-Specific Treatment Protocols
Thrombotic Thrombocytopenic Purpura (TTP)
Daily plasma exchange for a minimum of 5-7 days, exchanging twice the blood volume with fresh-frozen plasma, represents the standard of care. 1, 3 Continue daily exchanges for 14 days or until ADAMTS13 antibodies become undetectable. 1 This must be combined with glucocorticoids (methylprednisolone 1g IV daily for 3 days) plus rituximab with or without caplacizumab—never use plasma exchange as monotherapy. 3
ANCA-Associated Vasculitis
For patients requiring dialysis or with rapidly increasing serum creatinine, perform 7-10 high-volume plasma exchange treatments using 60 mL/kg volume replacement. 1 For diffuse pulmonary hemorrhage, initiate daily treatments until bleeding stops, then continue every other day for a total of 7-10 treatments. 1 Discontinue cyclophosphamide after 3 months in patients who remain dialysis-dependent without extrarenal manifestations. 1
Guillain-Barré Syndrome
Treatment stratification depends on severity at presentation: 4
- Mild cases (can walk with/without aid but not run): 2 plasma exchanges reduce time to motor recovery onset from 8 to 4 days. 4
- Moderate cases (cannot stand unaided): 4 plasma exchanges are superior to 2, reducing time to walk with assistance from 24 to 20 days and improving 1-year full muscle strength recovery from 46% to 64%. 4
- Severe cases (mechanically ventilated): 4 plasma exchanges are sufficient; 6 exchanges provide no additional benefit. 4
Perform exchanges on alternate days for a total of 5-7 sessions. 2
Cardiac Transplant Antibody-Mediated Rejection
Perform 4-5 sessions over 10-14 days, exchanging 1-2 plasma volumes, combined with immunosuppression (never as monotherapy). 1 Some centers use daily or every other day exchanges for a minimum of 5 sessions. 1
Severe Optic Neuritis (Steroid-Refractory)
Administer 5-7 plasma exchange sessions on alternate days for patients with visual acuity ≤20/200 after completing high-dose IV methylprednisolone. 2 Immediately follow with rituximab (375 mg/m² weekly for 4 weeks or 1000 mg twice, 2 weeks apart) regardless of final etiology determination. 2
Technical Procedure Details
Vascular Access Requirements
Plasma exchange requires high blood flow rates, necessitating either peripheral venous access with large-bore catheters or central venous access (tunneled catheters, non-tunneled central lines, or arteriovenous fistulas/grafts). 5 Central venous catheters may cause discomfort and increase infection, clotting, or bleeding risk. 6
Separation Methods
Two primary technical methods exist: 7
- Centrifugal separation: Uses centrifugal forces to separate and remove blood components
- Membrane filtration: Separates plasma from cellular components through filtration
Both methods achieve the goal of removing disease mediators from plasma. 7
Replacement Protocols
Blood is reconstituted with albumin, fresh-frozen plasma, or crystalloid before reinfusion. 1 The choice depends on the clinical indication and coagulation status. 1, 3
Critical Safety Considerations and Monitoring
Complications and Mortality
Overall mortality is estimated at 0.05% based on systematic reviews of >15,500 patients. 1 In Guillain-Barré patients, plasma exchange does not increase risk of infection, blood pressure instability, cardiac arrhythmias, or pulmonary embolism. 1
Essential Monitoring Parameters
- Hemodynamic changes and volume shifts
- Coagulation abnormalities and increased bleeding risk
- Electrolyte imbalances
- Line-related thrombosis
- Disease-specific markers (ADAMTS13 in TTP, platelet count, LDH, haptoglobin, renal function)
Drug Interactions
Plasma exchange nonselectively removes proteins and may affect pharmacokinetics of medications. 6, 1 Administer rituximab after plasma exchange, as the procedure removes the drug from circulation. 1
Common Pitfalls to Avoid
Never use fixed volumes without weight-based calculation—plasma volume varies significantly with body size. 1 Do not use plasma exchange as monotherapy; always combine with definitive treatment (immunosuppression, chemotherapy) as the procedure only provides temporary removal of pathogenic substances. 1, 3
Do not delay plasma exchange beyond 4-6 weeks of symptom onset in neurologic conditions, as early intervention improves outcomes. 2 In suspected TTP, start plasma exchange and glucocorticoids while awaiting ADAMTS13 results, as delays significantly increase mortality. 3
Avoid platelet transfusions in thrombotic microangiopathy unless life-threatening bleeding occurs, as they may worsen thrombotic complications. 3
Institutional Variability
Protocols for plasma exchange vary largely between medical institutions, and there is significant heterogeneity in plasma exchange protocols. 6 Access may be limited in some jurisdictions, and costs might not be covered by medical insurance, potentially requiring transfer to another center. 6