Giá trị của nồng độ NH₃, tiểu cầu trong dự báo giãn, vỡ tĩnh mạch thực quản ở bệnh nhân xơ gan

Background/Aims: The development of esophageal varices (EV) and resultant bleeding is the most critical complication of portal hypertension. Upper gastrointestinal endoscopy is the gold standard for the diagnosis of EV. To find a non-invasive method for the diagnosis of EV and to predict the bleeding risk is appealing and would decrease the cost and discomfort of upper endoscopy. The aim of our study was to evaluate blood ammonia and platelet levels as predictors of EV and EV bleeding in patients with liver cirrhosis. Materials and Methods: This was a cross-sectional study in which 187 patients were examined for endoscopy and measurement of blood ammonia and platelet levels at the 108 Military Central Hospital. Results: In the study, 61% of the 187 patients had large EV, while 39% had small or no EV. Serum ammonia and platelet levels were found to predict large EV with area under the receiver operating characteristic (AUROC) curves of 0.86 and 0.81, respectively, using cut-off values of 66.5 µmol/L and 105.5 G/L. The ammonia/platelet ratio was associated with the presence of large esophageal varices, with a cut-off value of 0.6 having 88.9% specificity. Moreover, a cut-off value of 73.6 µmol/L for blood ammonia levels could predict EV bleeding with a sensitivity of 76% and specificity of 70%. Conclusion: Our study indicates that serum ammonia levels can accurately predict the presence and size of EV in patients with liver cirrhosis with high sensitivity and specificity. Additionally, blood ammonia levels may be clinically useful as they correlate with and are independent predictors for esophageal variceal bleeding.