**6. Prometheus**

It is a fractionated plasma separation and adsorption system, the blood extracted through a catheter circulates through an AlbuFlow® AF01 filter, with a high screening coefficient (250 kD), which separates the albumin from the blood, the first to pass through the plasma to an adsorbent cartridge Prometh® 01 contains a neutrally charged, highly porous resin that absorbs bile acids, aromatic amino acids, and phenols. Then, the plasma and the albumin circulate through a second Prometh® 02 cartridge, which is an anion exchange resin in the form of chloride that allows the absorption of bilirubin, and following the sequence of the circuit, the blood plasma and the detoxified albumin are returned to the Fresenius® helixone high-flow filter to remove water-soluble toxins (**Figure 6**).

In the HELIOS study [36], an RCT included 145 patients with ACLF and compared SMT vs. SMT and Prometheus, in the survival outcomes at 28–90 days there were no statistical differences, the mean until death had no differences, and the severity of MELD and encephalopathy improved in the Prometheus group, in the univariate analysis there was no improvement in survival in patients with hepatorenal syndrome, the length of stay in critical care and the hospital was similar in both groups, and in the analytical the only value that improved it was the bilirubin.

#### **Figure 6.**

*Fractionated plasma separation and adsorption (Prometheus). A) The blood extracted through a catheter circulates through an AlbuFlow ® AF01 filter. B) Albumin and separated plasma pass to a Prometh® 01 adsorbent cartridge. C) Albumin then circulates through a second Prometh® 02 cartridge. D) Following the circuit sequence, blood plasma and detoxified albumin are returned to the Fresenius® helixone high-flow filter.*
