Cross-flow membrane plasmapheresis technique for continuous ex vivo plasma sampling

Area of Science:

• Biomedical Engineering
• Physiology
• Analytical Chemistry

Background:

• Accurate plasma concentration monitoring is crucial for pharmacokinetic studies.
• Traditional blood sampling methods can be invasive and may alter solute distribution.
• Continuous sampling techniques are needed for dynamic physiological processes.

Purpose of the Study:

• To develop and validate a novel technique for continuous plasma sampling.
• To assess the accuracy of this technique compared to existing methods.
• To highlight the advantages of this method for specific solute types.

Main Methods:

• Continuous membrane plasmapheresis was performed on blood in an extracorporeal arteriovenous shunt.
• The sampler utilized commercial planar microporous membranes (0.6-micron pore diameter).
• Validation involved low-molecular-weight solutes and ex vivo testing in rabbits.

Main Results:

• The technique provided time-averaged plasma concentrations comparable to serial and continuous withdrawal methods.
• Validation demonstrated reliable measurements for solutes with varying equilibration rates.
• Ex vivo tests confirmed the method's efficacy in a living system.

Conclusions:

• Continuous membrane plasmapheresis in an arteriovenous shunt is a viable method for plasma sampling.
• This technique offers advantages for monitoring solutes with dynamic distribution.
• It provides accurate time-averaged plasma concentrations, improving upon traditional methods.