 - Acute upper gastrointestinal bleeding: presence of hematemesis and or melena noted by the medical staff. Any acute gastrointestinal bleeding episode is defined as the presence of macroscopic signs of bleeding hematemesis, rectal bleeding, hematochezia and or melena noted by the medical staff. Severe gastrointestinal bleeding is defined as one that also present hemodynamic repercusion systolic blood pressure 100 mm Hg and heart rate 100 bpm or hemoglobin Hb 80 g l decrease in Hb 20 g l in 24 hours. 