Blood ammonia levels in liver cirrhosis: a clue for the presence of portosystemic collateral veins.

BACKGROUND: Portal hypertension leads to the formation of portosystemic collateral veins in liver cirrhosis. The resulting shunting is responsible for the development of portosystemic encephalopathy. Although ammonia plays a certain role in determining portosystemic encephalopathy, the venous ammonia level has not been found to correlate with the presence or severity of this entity. So, it has become partially obsolete. Realizing the need for non-invasive markers mirroring the presence of esophageal varices in order to reduce the number of endoscopy screening, we came back to determine whether there was a correlation between blood ammonia concentrations and the detection of portosystemic collateral veins, also evaluating splenomegaly, hypersplenism (thrombocytopenia) and the severity of liver cirrhosis. METHODS: One hundred and fifty three consecutive patients with hepatic cirrhosis of various etiologies were recruited to participate in endoscopic and ultrasonography screening for the presence of portosystemic collaterals mostly esophageal varices, but also portal hypertensive gastropathy and large spontaneous shunts. RESULTS: Based on Child-Pugh classification, the median level of blood ammonia was 45 mcM/L in 64 patients belonging to class A, 66 mcM/L in 66 patients of class B and 108 mcM/L in 23 patients of class C respectively (p < 0.001).The grade of esophageal varices was concordant with venous ammonia levels (rho 0.43, p < 0.001). The best area under the curve was given by ammonia concentrations, i, e., 0.78, when comparing areas of ammonia levels, platelet count and spleen longitudinal diameter at ultrasonography. Ammonia levels predicted hepatic decompensation and ascites presence (Odds Ratio 1.018, p < 0.001). CONCLUSION: Identifying cirrhotic patients with high blood ammonia concentrations could be clinically useful, as high levels would lead to suspicion of being in presence of collaterals, in clinical practice of esophageal varices, and pinpoint those patients requiring closer follow-up and endoscopic screening.

Mental status impairment in patients with West Haven grade zero hepatic encephalopathy: the role of HCV infection.

BACKGROUND: In patients with cirrhosis, subclinical hepatic encephalopathy, which negatively affects the activity of daily living, is often unidentified. In a multicenter observational study, we investigated the possibility of detecting minimal neurological changes consistent with subclinical hepatic encephalopathy by using the Trail Making Test in a cohort of patients with liver cirrhosis at hospital admission. METHODS: Seventy-seven consecutive patients with liver cirrhosis were studied (mean age, 69.5 +/- 9.1; 95% confidence interval, 67.5-71.6 years). In all patients, possible encephalopathy was investigated according to the West Haven criteria. All those free of any sign of encephalopathy (West Haven 0) were also studied by the Trail Making Test forms A and B. The Child-Pugh score was determined in all patients, and results were compared with the West Haven stage. Exclusion criteria were use of benzodiazepine, beta adrenergic blockers, alcohol, or antiepileptic drugs, or coexistence of depression, dementia, Parkinson's disease, or chronic or acute cerebral vasculopathy. RESULTS: Of the 77 patients, 44 (57.1%, 23 men and 21 women) had West Haven score 0, but among these, 26 (59.1%) were diagnosed with mental impairment likely linked to minimal hepatic encephalopathy. Severity of liver disease correlated with the presence of likely minimal hepatic encephalopathy, because the prevalence of abnormal Trail Making Test results increased from 22.2% in Child-Pugh A, to 63.4% and 74.0% in Child-Pugh B and C, respectively. CONCLUSIONS: The investigation of patients with cirrhosis by the West Haven test is not sufficient to identify subclinical forms of encephalopathy. The Trail Making Test (a simple, inexpensive test) in our series evidenced poor psychometric performance in more than half of the patients who were free of manifest encephalopathy. Subclinical hepatic encephalopathy was present mostly in patients with HCV-related cirrhosis. Detecting minimal hepatic encephalopathy in patients with cirrhosis may help improve their quality of life.