摘要BACKGROUND:Currently,prophylactic antibiotics are recommended only for cirrhotic patients with acute upper gastrointestinal bleeding(AUGIB);however,the benefit for other AUGIB patients remains undetermined.We aimed to compare the clinical outcomes between patients with AUGIB with and without prophylactic antibiotics to identify the population that requires this therapy.METHODS:Patients with AUGIB admitted between 1st January 2019 and 31st December 2021 in the Emergency Department of Peking Union Medical College Hospital were enrolled.Patients were divided into the antibiotic and non-antibiotic groups.The primary outcome was in-hospital mortality,and the secondary outcome was the onset of new infection.The risk factors for mortality and infection were analyzed,and stratification analysis of prophylactic antibiotics was performed.Continuous data were analyzed using the t-test or nonparametric rank sum test,and categorical data were analyzed using the Chi-square test or Fisher's exact test.Indicators with significant differences between the groups were included for logistic regression analysis.A P-value＜0.05 was considered statistically significant.RESULTS:A total of 392 individuals were included,among them,281 patients received prophylactic antibiotics,and 111 patients did not receive prophylactic antibiotics.The mortality rates were significantly lower in the antibiotic group than in the non-antibiotics group(6.41％vs.17.12％,P=0.001).The risk factors for infection were varicose veins(P=0.045)and endotracheal intubation(P=0.005)in the prophylactic antibiotic group,and endoscopic treatment(P=0.010)in the non-prophylactic antibiotic group.Stratified analyses showed that patients with age ≥ 65 years,endotracheal intubation,endoscopic treatment,and AUGIB of variceal etiologies benefited from prophylactic antibiotics.CONCLUSION:AUGIB patients may benefit from prophylactic antibiotics to decrease mortality,especially those aged ≥ 65 years and those with endotracheal intubation,endoscopic treatment,and variceal etiologies.