Russian Consensus on “Hyperammonemia in Adults”: The 2021 Version (in English)

Abstract

Hyperammonemia is an acute or chronic intoxication with ammonia and ammonium associated with elevated ammonia levels in serum due to either its increased production and/or decreased detoxification. Hyperammonemia can result from a variety of causes and clinically presents with unspecific signs and symptoms, including asthenia, encephalopathy, liver steatosis or fibrosis, and sarcopenia. With impaired liver function, hyperammonemia most frequently manifests in (micro)encephalopathy. Thus in case of unexpect change in mental status hyperammonemia must be excluded as fast as possible. An express method of photometric assay is informative enough to determine the ammonia levels. The following hyperammonemia classification is proposed: a) by ammonia levels (normal level: ≤ 60 μmol/L; mild (Grade 1): ≤ 100 μmol/L; moderate (Grade 2): ≤ 200 μmol/L; and severe (Grade 3): > 200 μmol/L); b) by etiopathogenesis (hereditary (congenital), functional (physiological), acquired (hepatic, extrahepatic, mixed)); c) by clinical presentation (transient, recurrent or persistent, constant (stable, without treatment), covert). Treatment for hyperammonemia is aimed at treating the primary disease and includes a diet that is restricted in animal protein but contains sufficient vegetable protein, limited physical activities, and use of intestinal non-absorbable antibiotics (rifaximin- alpha) as well as pre- and probiotics. L-ornithine- L-aspartate (LOLA) is a baseline therapeutic product administered in a number of scenarios to correct the level of hyperammonemia.