Introduction: Levels of sepsis-associated aromatic microbial metabolites (AMMs) of tyrosine and phenylalanine in the blood serum were demonstrated to correlate with severity of critical condition, particularly with SOFA score, and levels of some mitochondrial metabolites, reflecting the impact on mitochondrial dysfunction [DOI:10.3390/metabo9100196].

Objectives: To assess the extracorporeal detoxification effect on the AMM (including phenyllactic, 4-hydroxyphenylacetic, and 4-hydroxyphenyllactic acids) and mitochondrial metabolite (fumaric, succinic, and itaconic acids) dynamics, and their relationship with the severity assessment of intensive care patients.

Methods: Two critically ill patients (A and B) after severe injury, and patient C after complex cardiac surgery, underwent several sessions of hemodiafiltration and hemoperfusion due to development of multiple organ failure and sepsis. Metabolite concentrations in the serum samples (n=27) were detected using gas chromatography–mass spectrometry.

Results: In patients A and B with septic complications on the 1^st day, SOFA scores were 12 and 10 points, and AMM was 5 and 9 µM, respectively. Extracorporeal therapy was carried out over the next few days. On the 4^th and 6^th day for patients A and B, respectively, their condition was improved, and by the 13^th and 7^th day, SOFA scores and AMM reached their minimum values (3 µM for AMM), respectively [DOI:10.1134/S106193482470117X]. Patient C developed multiple organ dysfunction and demonstrated animprovement from 8 to 2 SOFA scores and from 38 to 5 µM after using extracorporeal therapy over 13 days. All three patients survived. The general direction of the dynamics of the SOFA scores and the AMM and mitochondrial metabolites coincided, at the same time, and the AMM positive dynamics was about one day ahead of the SOFA score for patients A and B.

Conclusion: Monitoring AMM levels may be useful for evaluating the effects of extracorporeal therapy in critically ill patients.