Serum ammonia as a non-invasive marker for early prediction of esophageal varices

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.

Small varices in chronic liver diseases

PURPOSE OF REVIEW

Gastroesophageal varices are common complications of chronic liver diseases (CLDs) and portal hypertension. Small varices have the risk of progressing to larger varices, causing bleeding or even death. Thus, early detection and appropriate management of small varices are necessary. The purpose of this review is to summarize the advance in the recent 5years about diagnosing and managing the small varices in CLDs.

RECENT FINDINGS

The diagnosing methods of small varices in recent studies include improved endoscopic examinations, such as capsule endoscopy, and many noninvasive methods, including blood tests, ultrasound, computed tomography and magnetic resonance. For the management of small varices, though it is controversial, prevention using nonselective beta-blockers is still an essential part.

SUMMARY

In this review, we summarize the classification of varices, the invasive and noninvasive diagnostic methods, their performances, and the emerging progression in the management of small varices in the recent 5 years. We hope that this review provides relevant information to understand better and appropriately manage small varices.

A review of wearable biosensors for sweat analysis

Recent advances in the skin-interfaced wearable sweat sensors allow a personalized daily diagnosis and prognosis of the diseases in a form of a non-invasive, portable, and continuous monitoring system. Especially, the soft microfluidic system provides robust quantitative analysis platforms that integrate sweat sampling, storing, and various sensing capabilities. This review systematically introduces the sweat collecting mechanism using soft microfluidic valves, including calculation of sweat storage and loss. In terms of sweat analysis, colorimetric (e.g. enzymatic, chemical, or their mixed reactions), electrochemical (e.g. voltammetric, potentiometric, amperometric, or conductometric), and multiplex measurements of sweat contents facilitate diagnosis of diseases via analysis of combined multiple data, such as vital signals (e.g. ECG, EMG, EEG, etc.) and information from the skin (e.g. temperature, GSR, etc.). The integration of wireless communication with the microfluidic systems enables point-of-care health monitoring for disease and specific physiological status.