Background: Acute upper gastrointestinal hemorrhage is a life-threatening condition that necessitates treatment within the first hour at the emergency department. Although prompt blood transfusion is one resuscitation procedure that can be implemented in these cases, its indications are not well understood.

Objective: To study factors that affect transfusion of uncross-matched type-O pack red cells (UOPRC) in acute upper gastrointestinal hemorrhage at the emergency department of a tertiary university hospital.

Materials and Methods: This was a cross-sectional analytical study. The population was acute upper gastrointestinal bleeding
patients at the Srinagarind Hospital emergency department (Khon Kaen University Faculty of Medicine) from August 1, 2016 to August 31, 2019. Data were collected by reviewing Health Object program (Hospital data) and Medical charts. Multiple Logistic regression analysis was performed to determine which factors were associated with transfusion of UOPRC and to study the mortality rate in these patients.

Results: The three risk factors found in the UOPRC group were heart rate >100 bpm (OR 4.60, p<0.05, 95% CI 1.794, 12.126), shock index >0.8 (OR 3.78, p<0.05, 95% CI 1.464, 10.706), and history of blood transfusion (OR 2.96, p<0.05, 95% CI 1.126, 7.723). The mortality rate was 29% in the UOPRC group and 1.1% in the non-UOPRC group.

Conclusion: Heart rate >100 bpm was the main factor associated with transfusion of UOPRC in acute upper gastrointestinal hemorrhage patients at the Srinagarind Hospital emergency department. Further research should be conducted based on the results from the present study to establish emergency blood transfusion criteria.

Keywords: Blood transfusion, Gastrointestinal hemorrhage, Emergency department, Tertiary hospital