Optimum Conditions for the Efficacy and Safety of Cryofiltration Apheresis: An Analysis of Circuit Temperatures Depending on Plasma Flow Rate and Cooling Coil Lengths/Turns

Abstract

A system providing both appropriate cooling and warming are needed for the efficacy and safety of cryofiltration (CF) plasmapheresis. We measured some points of CF circuit temperatures with varying plasma flow rates (QP = 10-40 mL/min) and the numbers of connecting cooling coils (one or two) under the conditions of blood flow rate (QB ) 100 mL/min with 7700-mm coil length, 19 turns, and 50-mL priming volume. We measured the respective temperatures of each point of starting/returning for an extracorporeal circuit (TA /TV ), intracooling coil (TC ), and post-plasma fractionator (PF) (TPF ). The subtraction of TV from TA (ΔT) was used as an indicator of safe return. There were no significant differences in TC , TPF , or ΔT in accordance with each QP between that of one and two coils. All of the Tc values under the condition QP ≤ 20 mL/min achieved <4°C. The TPF under the condition QP ≥ 20 mL/min was not significantly different compared to that of QP 30 mL/min (the lowest condition). Although the ΔT increased depending on the QP increase, the ΔT under the condition QP ≤ 15 mL/min was not significantly different from that of the control (one-way double-filtration plasmapheresis [DFPP]) group. We conclude that (i) one coil is enough for effective cooling in CF, and (ii) an ideal QP that fulfills the required conditions for both effective cooling and sufficient warming of returning fluid does not exist, but QP from 15 to 20 mL/min may be a relevant range.

Efficacy of Cryofiltration for Treatment of Mixed Cryoglobulinemia: A Report of Four Cases

“…The total volume of the plasma processed varied from 2000 mL to 3000 mL per treatment, depending on the body weight of the patients (approximately 50 mL/kg). Our method of cryofiltration is very similar to that previously reported except the plasma separator and fractionator.…”

“…We have successfully treated four cases suffering from severe and progressive manifestations of cryoglobulinemic vasculitis, in which cryofiltration was safe and effective in conjunction with immunosuppressive therapies and antiviral therapies. It been applied for the treatment of cryoglobulinemic vasculitis . Three of the cases had cryoglobulinemia secondary to HCV infection.…”

“…Then remaining plasma is warmed and returned to the patient. Although its efficacy has not yet been well established, it has been applied for the treatment of cryoglobulinemic vasculitis . Here we report four cases with mixed cryoglobulinemia showing severe and progressive clinical manifestations undergoing cryofiltration treatment.…”