Plasma exchange is used as primary, adjunctive, or supportive therapy for a variety of clinical disorders. Although plasma exchange is considered a reasonably safe procedure, acute complications can occur and include citrate toxicity, vasovagal reactions, allergic reactions, respiratory distress, seizures, myocardial infarction, and very rarely death. A long-term concern is chronic blood loss with repeated plasma exchange procedures. Each apheresis procedure involves an extracorporeal volume that depends on the particular apheresis instrument and use of an in-line blood warmer. Blood warmers are routinely used during apheresis to increase patient comfort and safety. Although currently available apheresis instruments perform a final rinseback, a number of red blood cells remain in the instrument and blood warmer at the completion of the procedure. This loss is not significant in most adults undergoing only a few apheresis procedures, but may become important in patients with small red cell masses or who require frequent, long-term apheresis therapy. Repeated plasma exchange procedures in patients with ongoing bleeding, hemolysis, iron deficiency, renal failure, compromised marrow reserve, or other significant iatrogenic losses of blood may lead to anemia or exacerbate an existing anemia ultimately requiring or increasing the need for transfusion. Therefore, we attempted to quantitate the amount of red blood cells lost at the completion of a typical plasma exchange procedure with or without the use of an in-line blood warmer.
Twelve patients underwent a total of sixteen 1.0 plasma volume therapeutic plasma exchanges with 5% albumin solution as part of their regularly scheduled treatment for a variety of disorders including familial hypercholesterolemia, primary biliary cirrhosis, chronic inflammatory demyelinating polyneuropathy, myesthenia gravis, pemphigus vulgaris, multiple sclerosis, hyperviscosity, and cyrofibrinogenemia. The plasmapheresis procedures were performed using a COBE Spectra apheresis instrument (COBE BCT, Inc., Lakewood, CO). Venous access and return were obtained either peripherally via 16-gauge needles or by central venous catheter.