Objectives: Prehospital antibiotic administration prior to emergency department (ED) admission could reduce the delay of effective antibiotic treatment and thus mortality of septic patients. Additionally, collecting blood cultures early could improve microbial identification. We assessed the effect of ceftriaxone administration before ED admission on mortality. As our secondary objective, we evaluated the positivity and contamination rate of prehospital blood cultures in a prehospital physician-staffed system.

Methods: The computerized databases of a physician-staffed prehospital unit were screened for patients presenting with suspected sepsis and low systolic blood pressure (< 90 mmHg) between May 2013 and December 2018. The association between prehospital ceftriaxone administration and 28-day mortality, Intensive care unit (ICU) admission and length-of-stay (LOS) was analyzed. The yield of blood cultures and frequency of contamination were calculated.

Results: A total of 165 septic patients matched the inclusion criteria. Prehospital antibiotics were administered in 60.6% (100/165) of cases. Twenty-eight-day mortality was similar between patients receiving and not receiving antibiotics (39.0 % vs 38.5%, p  = 1.000). Hazard ratio of 28-day mortality was 0.87 (95%IC 0.51-1.47). Likewise, no statistically significant impact on 7-day mortality, ICU admission or LOS was found. Blood cultures showed a high positivity rate (35.4%, 23/65) and a low contamination rate (3.1%, 2/65).

Conclusions: In a physician-staffed prehospital system, prehospital blood cultures among critically ill, septic patients showed high positivity and low contamination rates. However, early ceftriaxone administration showed no impact on 28-day mortality, 7-day mortality, ICU admission and ED and ICU LOS.