Association between early prehospital administration antibiotic and 28-day mortality in sepsis

OBJECTIVES: Sepsis is a life-threatening emergency requiring prompt recognition and timely treatment. Delayed antibiotic administration is consistently associated with increased mortality. However, evidence regarding the impact of empirical antibiotic administration in the prehospital setting on mortality outcomes remains limited. This study aimed to evaluate the association between prehospital antibiotic administration and 28-day mortality among patients with suspected sepsis. METHODS: An observational cohort study was conducted at the Emergency Medical Operation Unit, Ramathibodi Hospital, from September 1, 2022, to September 30, 2025. Patients aged ≥18 years with suspected sepsis in prehospital care were included. Adjusted absolute risk reduction (ARR) was estimated to compare 28-day mortality between prehospital antibiotic administration and usual care. Multivariable logistic regression adjusted for the Charlson Comorbidity Index, Ramathibodi early warning score, modified Sequential Organ Failure Assessment score without creatinine, intravenous fluid volume, blood lactate level, scene time, distance from the scene to the hospital, vasopressor administration, and prehospital intubation was performed to assess the independent association between prehospital antibiotic administration and 28-day mortality. Multivariable linear regression was performed to compare differences in time to antibiotic administration and scene time between prehospital antibiotic administration and usual care groups. RESULTS: A total of 364 patients were enrolled, of whom 154 (42.3%) received prehospital antibiotics, and 210 (57.7%) did not. The 28-day mortality rate was 25.9% in the prehospital antibiotic group and 28.1% in the usual care group. The adjusted ARR was 8.9% (95% Confidence Interval [CI] 0.8 - 17.1%; p = 0.031), and the adjusted odds ratio was 0.51 (95% CI 0.27 - 0.95; p = 0.035). The adjusted mean difference in time to antibiotic administration was significantly shorter in the prehospital group (-124.6 minutes; 95% CI -183.9 - -65.2; p <0.001), whereas scene time increased by 8.5 minutes (95% CI 5.2-11.8; p <0.001). CONCLUSIONS: Prehospital antibiotic administration was associated with a lower 28-day mortality among patients with suspected sepsis. Further multicenter studies are warranted to confirm these findings and improve prehospital sepsis management protocols.