This project aims to collect the exhaled breath of patients with acute upper gastrointestinal bleeding clinically, divide them into large, small and no bleeding groups according to the results of gastroscopy, analyze the characteristics of volatile organic compound components in exhaled breath, construct a discriminant model, and then analyze the sensitivity and specificity, and the target sensitivity and specificity reach more than 0.7, and formulate diagnostic criteria.

Upper gastrointestinal bleeding is one of the most common gastrointestinal emergencies and has a high mortality rate. Its clinical manifestations are hematemesis and melena, gastroscopy is the gold standard for diagnosing upper gastrointestinal bleeding, but due to its expensive equipment, long training cycle of personnel, gastroscopy itself is an invasive operation, poor patient tolerance, high risk of examination, often lead to the diagnosis of upper gastrointestinal bleeding is not timely, missing the best treatment time. Volatile organic compound analysis in exhalation is based on the patient's metabolic component analysis technology, a new means of disease diagnosis, due to its advantages of convenient collection, non-invasive, rapid detection, etc., it has been applied in the diagnosis of various diseases such as drunken screening and Helicobacter pylori infection, but has not been studied in the diagnosis of upper gastrointestinal bleeding. This project aims to collect the exhaled breath of patients with acute upper gastrointestinal bleeding clinically, divide them into large, small and no bleeding groups according to the results of gastroscopy, analyze the characteristics of volatile organic compound components in exhaled breath, construct a discriminant model, and then analyze the sensitivity and specificity, and the target sensitivity and specificity reach more than 0.7, and formulate diagnostic criteria. This study will improve the timeliness of upper GI bleeding detection, which is of great significance for effectively reducing the mortality rate of upper GI bleeding.

Inclusion Criteria: upper GI bleeding patients -

Exclusion Criteria: Severe cardiopulmonary disease

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upper GI bleeding patients who will under go endoscopy examination