Serum Ammonia Levels as a Non-invasive Predictor of the Presence and Severity of Esophageal Varices in Chronic Liver Disease Patients

Background Portal hypertension leads to the formation of portosystemic collateral veins, of which esophageal varices (EV) are the most severe complications and have the greatest clinical impact. The possibility of identifying cirrhotic patients with varices by non-invasive tests is appealing, as they can lead to reduced healthcare costs and can be done in resource-limited settings. In this study, we investigated ammonia as a potential non-invasive predictor of EV. Methods This was a single-center cross-sectional observational study that was done at a tertiary health care hospital in north India. It included 97 chronic liver disease patients irrespective of etiology after excluding patients with portal vein thrombosis and hepatocellular carcinoma to participate in endoscopic screening for the presence of EV and correlate it with various non-invasive markers like serum ammonia levels, thrombocytopenia and aspartate aminotransferase to platelet ratio index (APRI ). On the basis of endoscopy, enrolled patients were divided into two groups, i.e., group A consisting of large varices (grade III and grade IV) and group B consisting of patients with low-grade varices and no varices (grade II, grade I, and no varices). Results This study included 97 patients, out of which 81 patients have varices on endoscopy, and mean serum ammonia levels were found to be significantly higher in cases with varices (135 ±69.70 ) vs. those without varices (94±43) (p value=0.026). Further, on comparing serum ammonia values between patients with large varices (Grade III/IV) (Group A) with a mean value of 176 ± 83 vs. Grade I/II/No varices (Group B) with a mean value of 107±47, which were significantly higher in Group A patients (<0.001). In our study, we also found a correlation between blood urea level as a non-invasive predictor of varices, but no statistically significant relation was found between thrombocytopenia and APRI. Conclusion This study found that serum ammonia can be used as a useful marker for the prediction of EV and can also be used to determine the severity of varices. Apart from ammonia, serum urea levels can also prove to be a good non-invasive marker for the prediction of varices although further multicentric studies are warranted to reach this conclusion.