272 Septic Patients Often Present Without Obvious Bacterial Infection

Abstract

Consensus recommendations and national quality guidelines have strongly emphasized early recognition and treatment of sepsis. We hypothesized that septic patients often present without obvious bacterial infection. During scheduled hours in a single academic ED, we prospectively enrolled all adult patients with abnormal vital signs (SBP <100, SI >1, RR >=22, or GCS<15) prior to diagnostic testing results. We excluded patients with acute trauma, acute stroke, or STEMI. Prior to diagnostic testing results and directly after initial patient evaluation, we queried the ED attending physician for their clinical suspicion of bacterial infection [very low <10% likelihood (not working up infection), possible 10-50% likelihood (infection on differential diagnosis), probable 51-90% likelihood (infection top of the differential diagnosis), definite >90% likelihood]. The outcomes, presumed bacterial infection and sepsis, were defined as per CDC surveillance guidelines: 1) patients who received blood cultures (BCx) and 4+ days of qualifying antibiotics (QADs), and 2) presumed bacterial infection in the presence of organ dysfunction. We used the Cochran-Armitage test for trend to confirm that higher risk strata of infection suspicion were significantly associated with bacterial infection rates. We enrolled 620 patients. There were 200 (32%; 29-36%[95% CI]) with presumed bacterial infection and 82 (13%; 11-16%) with sepsis. Proportions of the bacterial infection suspicion strata were significantly associated with rates of presumed bacterial infection: very low 11% (7-16%[95% CI]); possible 34% (28-40%); probable 71% (61-80%); and definite 100% (79-100%); with p-value<0.0001 for trend. For the 82 septic patients, the distribution of physicians’ initial “clinical suspicion for bacterial infection” was: very low: very low 6% (2-14%[95% CI]); possible 52% (41-64%); probable 35% (25-47%); and definite 6% (2-14%). In patients with abnormal vital signs, emergency physicians were able to accurately quantify patients’ risk of infection prior to diagnostic testing (ie, agreement between physicians’ estimates of bacterial infection risk and rate of presumed bacterial infection). Yet for septic patients, only a minority had “probable” or “definite” infection suspected prior to diagnostic testing. This highlights that early identification of sepsis can be challenging, requiring consideration even in patients with lower pre-diagnostic suspicion.