Changes of Ammonia Levels in Patients with Acute on Chronic Liver Failure Treated by Plasma Exchange

Background/Aims: Acute on chronic liver failure (AoCLF) is associated with a high mortality rate. Plasma exchange (PE) is useful to bridge AoCLF patients to liver transplantation: The aim of this study was to assess the effects of PE on plasma ammonia levels (PAL) in AoCLF patients. Methodology: Seventy patients with AoCLF in 2 groups (PE plus standard medical treatment group, n = 32; and standard medical treatment group, n = 38) were enrolled in study. PAL was detected on admission and on days 7, 14, 21, and 30 during hospitalization. Results: All AoCLF patients showed PAL more than the upper limit of the normal range. More dramatic decreased in the PE survivors (form 116.8 +/- 36.3 to 44.8 +/- 16.3, p < 0.01) than the medical survivors (form 105.7 +/- 30.2 to 57.1 +/- 20.3, p < 0.05) after 30 days of treatment. Furthermore, PAL after medical treatment were still higher than those of PE treatment in the survivors (57.1 +/- 20.3 vs. 44.8 +/- 16.3, p < 0.05). Among the non-survivors in the medical group, PAL remained at high levels throughout the examination period. Importantly, an increased PAL associated with high mortality and reduced survival time of AoCLF patients. Conclusions: Ammonia may be important in the pathogenesis of the AoCLF and PE may represent a reliable hepatic support device for AoCLF.