Membrane Plasma Exchange by Single-Needle Hemofiltration Device

Abstract

Membrane plasma exchange can be performed by the use of a double-pump hemofiltration device with only one central venous Shaldon catheter. According to this single-needle technique the intermittent blood flow is controlled by pressure monitoring resulting in a continuous filtration flow of 70 m1/min which is quantitatively replaced by an albumin (30 g/l) substitution fluid. Thus, a 4,000-m1 plasma exchange can be performed within 1 h and an equal or even better sieving coefficient for IgG (S = 0.81) is achieved compared with the continuous technique using two vascular accesses.

Single-Needle Membrane Plasmapheresis

“…There was an overall reduction in immunoglobulin and complement concen tration of 43-65% after the plasmapheresis sessions, dependent on the filter type and the protein component studied. There were no significant differences in overall extraction 8.36 ± 1.42 mg/100 ml, and no major differ ences between the three filters studied were observed.…”

“…Although the in vivo clearing capacities of different plasma separators during single needle plasmapheresis has as yet not fully been explored, some authors claim that pro voking a discontinuous oscillating blood flow during plasma exchange may cause a more effective elimination profile than the usual filtration technique with continuous flow [8,9], The mechanism to explain this finding may be a less pronounced formation of polarization protein layer on the filter due to the pulsatile capillary blood flow in the single-needle blood circuit. The present data indicate that sieving coefficients are at least as good with this single-needle method as with the more frequently used two-needle method.…”