The importance of bacterial infections as precipating factors of chronic hepatic encephalopathy in cirrhosis.

Background/aims: It is generally accepted that chronic hepatic encephalopathy (HE) is a stable form of neuropsychiatric disorder, usually related to porto-systemic shunts and with no exogenous precipitating factors. Bacterial infections are frequent causes of morbidity in cirrhosis, including the development of HE in its acute form, but there are no reports of its role in chronic forms of HE.

Methodology: We studied 168 episodes of hepatic encephalopathy in 111 patients with cirrhosis who were admitted to hospital during the last four years. Clinical staging was used for the diagnosis of acute and chronic HE, complemented by number connection tests and EEG. In chronic HE the diagnostic criteria were intolerance to animal proteins and a continuous need for medications and/or special diets. Alcohol was the etiology of cirrhosis in 81.1% of patients, hepatitis B or C virus in 12.6% and various factors in 6.3%. The male/female ratio was 3:1 and mean age was 53 years.

Results: Twenty patients (18%) were characterized as having chronic HE, whereas ninety-one (82%) presented acute HE. Precipitating factors could be detected in 43 out of 57 (75.4%) of chronic forms and in 108 of 111 (97.3%) episodes of acute HE. Bacterial infections were associated with HE in 15 of 43 cases (34.8%) of chronic HE and in 37 of 108 (34.7%) cases of acute HE (p < 0.05). Spontaneous bacterial peritonitis was the most prevalent infection in acute HE, whereas urinary tract infection was most frequent in chronic HE. Mortality was higher in acute than in chronic HE (p < 0.001), associated with Child C prognostic classification, grades III and IV of HE and more severe precipitating factors.

Conclusions: The diagnosis and control of precipitating factors, especially bacterial infection, should also be considered during the treatment of chronic hepatic encephalopathy.