Hemoperfusion: technical aspects and state of the art

Abstract

Background: Blood purification through the removal of plasma solutes by adsorption to beads of charcoal or resins contained in a cartridge (hemoperfusion) has a long and imperfect history. Developments in production and coating technology, however, have recently increased the biocompatibility of sorbents and have spurred renewed interest in hemoperfusion.

Methods: We performed a narrative assessment of the literature with focus on the technology, characteristics, and principles of hemoperfusion. We assessed publications in ex vivo, animal, and human studies. We synthesized such literature in a technical and state-of-the-art summary.

Results: Early hemoperfusion studies were hampered by bioincompatibility. Recent technology, however, has improved its safety. Hemoperfusion has been used with positive effects in chronic dialysis and chronic liver disease. It has also demonstrated extraction of a variety of toxins and drugs during episodes of overdose. Trials with endotoxin binding polymyxin B have shown mixed results in septic shock and are under active investigation. The role of non-selective hemoperfusion in sepsis or inflammation remains. Although new technologies have made sorbents more biocompatible, the research agenda in the field remains vast.

Conclusion: New sorbents markedly differ from those used in the past because of greater biocompatibility and safety. Initial studies of novel sorbent-based hemoperfusion show some promise in specific chronic conditions and some acute states. Systematic studies of novel sorbent-based hemoperfusion are now both necessary and justified.

Fig. 1

Schematic configuration of direct hemoperfusion (HP). Qb_i = Blood flow at the inlet of the unit; Q_f^Net = net ultrafiltration

Fig. 2

Schematic configuration of hemoperfusion combined with hemodialysis (HP-HD) and hemoperfusion combined with continuous renal replacement therapy (HP – CRRT). Qb_i = Blood flow at the inlet of the unit; Qb_o = Blood flow at the outlet of the units; Qd_i = Dialysate flow at the inlet of the dialyzer; Qd_o = Dialysate flow at the outlet of the dialyzer; Q_f^Net = net ultrafiltration

Fig. 3

Schematic configuration of plasmafiltration-adsorption (PFAD) or continuous plasmafiltration-adsorption (CPFA). Qb_i = Blood flow at the inlet of the plasmafilter; Qb_o = Blood flow at the outlet of the plasmafilter; Qp_f = Plasmafiltrate flow; Qp_r = Plasma Reinfusion flow; Q_f^Net = net ultrafiltration

Fig. 4

Schematic configuration of plasmafiltration-adsorption combined with hemodialysis (PFAD-HD) or continuous plasmafiltration-adsorption combined with continuous renal replacement therapy (CPFA-CRRT). Qb_i = Blood flow at the inlet of the units; Qb_o = Blood flow at the outlet of the units; Qp_f = Plasmafiltrate flow; Qp_r = Plasma Reinfusion flow; Qd_i = Dialysate flow at the inlet of the dialyzer; Qd_o = Dialysate flow at the outlet of the dialyzer; Q_f^Net = net ultrafiltration

Fig. 5

Schematic configuration of double plasmafiltration molecular adsorption system (DPMAS). Qb_i = Blood flow at the inlet of the unit; Qb_o = Blood flow at the outlet of the plasmafilter; Qp_f = Plasmafiltrate flow; Qp_r = Plasma Reinfusion flow; Q_f^Net = net ultrafiltration

Fig. 6

Schematic configuration of direct hemoperfusion combined with extracorporeal membrane oxygenation (HP-ECMO). Qb_{i HP} = Blood flow at the inlet of the hemoperfusion unit; Qb_{o HP} = Blood flow at the outlet of the hemoperfusion unit; Qb_{i ECMO} = Blood flow at the inlet of the ECMO circuit; Qb_{o ECMO} = Blood flow at the outlet of the ECMO circuit