Gastrointestinal bleeding is a condition that frequently presents to emergency departments and can be fatal if diagnosis and treatment are delayed. The working mechanism of end tidal capnography is simply to detect the respiratory carbon dioxide level.

In our study, the investigators aimed to determine the severity of gastrointestinal bleeding by using the Glaskow Blachford Score and AIMS65 score in cases presenting with gastrointestinal bleeding, to determine the end tidal carbon dioxide value by capnography in these cases and to determine its effectiveness in evaluating mortality and morbidity in gastrointestinal bleeding.

Gastrointestinal (GI) bleeding is a condition that frequently presents to emergency departments and has a mortal course in case of delayed diagnosis and treatment. Upper GI bleeding accounts for 5% of emergency department admissions. Mortality rates vary between 2% and 15%. Mostly, GI bleeding stops spontaneously and does not require endoscopic intervention, blood transfusion or surgery. However, among patients with life-threatening bleeding, timely intervention is very important. For this purpose, there are widely used and validated risk stratification tools such as the Glasgow Blatchford Score (GBS) and the AIMS65 score.

Capnography involves the noninvasive measurement of CO2 partial pressure during the respiratory cycle. It provides information on ventilation (efficiency of carbon dioxide elimination), perfusion (vascular CO2 transport) and metabolism (CO2 production through cellular metabolism). The principle of end-tidal capnography (ETCO2) is to detect the level of carbon dioxide in the expiratory breath.ETCO2 waveform changes provide information to physicians in various situations such as assessment of disease severity, cardiac arrest (quality of compression, return of spontaneous circulation, endotracheal tube placement, prognosis) procedural sedation and prediction of critical illness.

In our study, the investigators aimed to determine the relationship of ETCO2 value with GBS and AIMS65 scores and its effectiveness on the evaluation of morbidity and mortality in patients admitted to the emergency department with GI bleeding.

Inclusion Criteria:

• Patients presenting to the emergency department with symptoms and signs of gastrointestinal bleeding (hematochezia, melena, hematemesis).
• Patients with a presumptive diagnosis of gastrointestinal bleeding confirmed by endoscopy and colonoscopy.
• Patients who consent to participate in the study.
• Patients aged 18 and older.

Exclusion Criteria:

• Patients without symptoms and signs of gastrointestinal bleeding.
• Patients with a presumptive diagnosis of gastrointestinal bleeding ruled out by endoscopy and colonoscopy.
• Patients with respiratory pathologies that increase CO2 levels (such as asthma, COPD, pneumonia, etc.).
• Patients referred from external centers and underwent ERT replacement.
• Patients with heart failure.
• Patients who refuse to participate in the study.