Methods and systems for removing carbon dioxide

Inventors

Kreymann, Bernhard • Hüßtege, Christoph

Assignees

Advitos GmbH

Abstract

Systems and methods suitable for extracorporeal lung support are provided that expose blood, across a semipermeable membrane, to a dialysis liquid. The dialysis liquid features a buffering agent and has a high buffering capacity for H+ ions. Carbon dioxide, bicarbonate and hydrogen cations are transported across a semipermeable membrane into the dialysis liquid. The dialysis fluid may be recycled and repeatedly used, and its pH may be adjusted, and other fluids added to it. Certain substances may be removed from the blood, and the amount of these substances removed from the blood may be substantially automatically or substantially continuously monitored or quantified. The systems and methods are suitable for treating or preventing respiratory acidosis, metabolic acidosis, and diseases featuring lung malfunction, kidney malfunction, or liver malfunction.

Core Innovation

The invention provides an extracorporeal dialysis approach for removing hydrogen cations (H+) from a biological fluid by exposing the biological fluid to a dialysis fluid across a semipermeable membrane in a dialyzer. The dialysis fluid comprises a pH in the range from pH 8.0 to pH 11.0, at least one buffering agent having a pKa value in the range of 7.0 to 11.0, and a buffering capacity of at least 12 mmol/l for H+ ions. By using a dialysis fluid with high buffering capacity at basic pH, the system enables H+ removal during dialysis.

The invention further enables automatic quantification of the amount of hydrogen cations removed from the biological fluid. The amount of H+ removed is calculated based on the buffering capacity of the dialysis liquid and the difference of the pH of the dialysis liquid entering the dialyzer and the pH of the dialysis liquid exiting the dialyzer. This quantification ties the measured pH change during dialysis to the buffering capacity to determine the quantity of H+ removed.

For extracorporeal blood treatment, the invention includes withdrawing blood from a subject, exposing the blood to the specified dialysis fluid across the semipermeable membrane, removing hydrogen cations from the blood, and returning the blood to the subject. In treatment of a subject suffering from an acid/base imbalance, the same dialysis-fluid composition and semipermeable membrane exposure are used, together with returning the biological fluid and performing automatic quantification using the pH difference and the dialysis fluid buffering capacity.

Claims Coverage

The document includes three independent claims, centered on a semipermeable-membrane dialysis system using a basic, high-buffering-capacity dialysis fluid. Across the independent claims, there are three main inventive features: the specific dialysis fluid composition, hydrogen-cation removal across the semipermeable membrane, and automatic quantification of removed H+ based on buffering capacity and the pH difference between dialysis-fluid entry and exit.

Across the independent claims, the coverage consistently requires a dialysis system with a dialyzer and semipermeable membrane, a dialysis fluid having pH 8.0 to 11.0 with buffering agents having pKa 7.0 to 11.0 and buffering capacity at least 12 mmol/l for H+ ions, hydrogen-cation removal during exposure across the membrane, and automatic quantification of removed H+ calculated from buffering capacity and the dialysis-fluid pH difference between entry and exit. The independent claims further extend this core concept to extracorporeal blood withdrawal/return and to treating a subject suffering from an acid/base imbalance.

Stated Advantages

Documented Applications