Ammonia levels and the severity of hepatic encephalopathy

Abstract

Objective: To evaluate the correlation between ammonia levels with the severity of HE in patients coming to the tertiary care hospital with liver cirrhosis and hepatic encephalopathy (HE).

Study design: Descriptive, analytical study.

Place and duration of study: Shifa International Hospital, Islamabad, from January 2011 to February 2012.

Methodology: A total of 135 patients with liver cirrhosis and HE had serum ammonia levels measured on admission. The diagnosis of HE was based on clinical criteria, and its severity was graded according to the West Haven Criteria for grading of mental status. Ammonia levels were correlated with the severity of HE using Spearman rank correlation.

Results: Out of 20 patients with normal ammonia levels, 13 (65%) were in HE I-II, 6 (30%) were in grade-III, while 1 (5%) patient was in grade-IV HE. Out of 45 patients with mild hyperammonemia, 27 (60%) were in grade I-II, 12 (26%) were in grade-III and 6 (13%) were in grade-IV HE. Out of 34 patients with moderate hyperammonemia, 9 (26%) were in grade I-II, 18 (53%) were in grade-III, and 7 (20%) were in grade-IV HE. Out of 36 patients with severe hyperammonemia, 31 (86%) patients were in grade-IV HE (p < 0.001).

Conclusion: Ammonia levels correlated with the severity of hepatic encephalopathy. Greater the ammonia level, severe is the grade of hepatic encephalopathy.