Albumin is a protein in the human body that is used to transport water-insoluble substances such as fatty acids, bilirubin, trace elements, certain vitamins, hormones, metals and drugs. All these substances become transportable by binding to albumin. In contrast to normal kidney dialysis, in which only water-soluble toxins are eliminated, the ADVOS process additionally removes protein-bound hepatotoxins and nephrotoxins as well as CO2.
After the patients are connected to the multi-organ support device ADVOS multi by a conventional port or Shaldon catheter, the blood contaminated with toxins is passed through the ADVOS dialyzers and purified by means of albumin-enriched dialysate.
The dialysate binds both water-soluble and protein-bound toxins and is subsequently purified of toxins in the unique ADVOS circuit by chemical-physical processes and the resulting filtrates are disposed.
The ADVOS circuit itself consists of two partial circuits:
Hydrochloric acid is introduced into the acid loop and due to a related pH reduction positively charged substances, such as, copper and CO2, are removed.
Sodium hydroxide solution is fed into the base loop, and a related pH increase results in negatively charged substances such as, for example, bilirubin and bile acids to be removed.
After filtration of the toxins, both loops are merged, hydrochloric acid and sodium hydroxide are neutralized to saline and water (HCl + NaOH = H2O + NaCl) and the purified, unsaturated albumin dialysate can be cycled through the dialyzer again in order to remove further toxins. Since the albumin is permanently purified and recycled, only a small amount of albumin is needed for efficient toxin removal.
In addition, control of the addition of acid and base also allows the pH of the dialysate to be altered, i.e. depending on the desired pH of the dialysate (7.2-9), the ADVOS multi adds either more acid or base.
The latter is important for the targeted treatment of metabolic or respiratory acidosis and CO2 removal.