When appropriate antibiotic therapy is relevant in bacteremic septic patients

Introduction

In the past 10 years different authors have published higher mortality in severe infection related to inappropriate antibiotic therapy (IAT). A systematic review [1] recommends defining groups of patients that could benefit more with appropriate antibiotic therapy (AAT).

Methods

Two hundred and twenty bacteremic septic patients admitted during 4 years to a medical–surgical ICU were considered for place of acquisition (community acquired vs nosocomial acquired), foci of origin, SAPS II and presence of shock, in relation to mortality and to the appropriateness of empiric antibiotic therapy. Mortality was considered during the ICU stay.

Results

For 220 septic patients, mortality in 106 patients (48%): AAT 157 patients (71.4%), mortality in 71 patients (45%); IAT 63 patients (28.6%), mortality in 35 patients (55.5%) (P = 0.2). Community-acquired bacteremia 153 patients, mortality in 73 patients (47%); nosocomial-acquired bacteremia 67 patients, mortality in 33 patients (49%) (P = 0.9). Community-acquired bacteremia 99 patients with SAPS II ≤50: IAT 23 patients, 12 dead; AAT 76 patients, 20 dead (P = 0.03, RR = 1.9). For 54 patients with SAPS II > 50 in this group the IAT was not related to mortality. See Table 1.

Table 1 Antibiotic therapy and mortality by foci of origin

Conclusion

IAT relates to unknown foci of origin in septic patients irrespective of the site of acquisition and severity of illness (P = 0.01, RR = 2.3). Bacteremic pulmonary infections treated with empirical IAT have a higher attributable mortality (P = 0.02, RR = 2.9). CA septic patients with SAPS II ≤50, when treated with IAT, have a significantly higher mortality (P = 0.03, RR = 1.9). We were not able to document this in more severely compromised patients (SAPS II > 50), probably because the severe septic condition hides the consequences of the IAT.