Mechanistic insight, diagnosis, and treatment of ammonia-induced hepatic encephalopathy

J Gastroenterol Hepatol. 2019 Jan;34(1):31-39. doi: 10.1111/jgh.14408. Epub 2018 Aug 19.

Abstract

Hepatic encephalopathy is a neuropsychological syndrome due to biochemical disturbance of brain function in advanced liver disease patients. Diagnosis and treatment of the condition is very demanding and has negative toll on finances with increased healthcare utilization. The pathophysiology is not completely understood; however, there is evidence that ammonia plays an important role in the etiology. Conventional methods of solely relying on blood ammonia level to diagnose hepatic encephalopathy did not help much; likewise, the use of lactulose alone in treating hepatic encephalopathy has also been discouraged. This paper analyzed the current knowledge regarding the mechanism of how ammonia disrupts the normal brain function as well as the use of latest diagnosing tools including those under development to evaluate the neuropsychiatric state of patients and their quality of life. The efficacies of lactulose and rifaximin combination for short-term and long-term treatment in addition to nutritional interventions and other drugs undergoing clinical trials were also reviewed.

Keywords: ammonia; hepatic encephalopathy; lactulose; liver disease; portosystemic shunt.

Publication types

  • Review

MeSH terms

  • Ammonia / metabolism*
  • Diet
  • Glutamine / metabolism
  • Hepatic Encephalopathy / diagnosis
  • Hepatic Encephalopathy / drug therapy*
  • Hepatic Encephalopathy / etiology*
  • Hepatic Encephalopathy / metabolism
  • Humans
  • Urea / metabolism

Substances

  • Glutamine
  • Ammonia
  • Urea