Bloodstream infections and sepsis in Greece: over-time change of epidemiology and impact of de-escalation on final outcome

Abstract

Background: Choice of empirically prescribed antimicrobials for sepsis management depends on epidemiological factors. The epidemiology of sepsis in Greece was studied in two large-periods.

Methods: Sepsis due to bloodstream infections (BSI) from July 2006 until March 2013 was recorded in a multicenter study in 46 departments. Patients were divided into sepsis admitted in the emergencies and hospitalized in the general ward (GW) and sepsis developing after admission in the Intensive Care Unit (ICU). The primary endpoints were the changes of epidemiology and the factors related with BSIs by multidrug-resistant (MDR) pathogens; the secondary endpoint was the impact of de-escalation on antimicrobial therapy.

Results: 754 patients were studied; 378 from 2006-2009 and 376 from 2010-2013. Major differences were recorded between periods in the GW. They involved increase of: sepsis severity; the incidence of underlying diseases; the incidence of polymicrobial infections; the emergence of Klebsiella pneumoniae as a pathogen; and mortality. Factors independently related with BSI by MDR pathogens were chronic hemofiltration, intake of antibiotics the last three months and residence into long-term care facilities. De-escalation in BSIs by fully susceptible Gram-negatives did not affect final outcome. Similar epidemiological differences were not found in the ICU; MDR Gram-negatives predominated in both periods.

Conclusions: The epidemiology of sepsis in Greece differs in the GW and in the ICU. De-escalation in the GW is a safe strategy.

Figure 1

Study flow-chart. Abbreviations BSI: bloodstream infection; ER: emergency department; ICU intensive care unit; SIRS: systemic inflammatory response syndrome.

Figure 2

Distribution of bloodstream pathogens between the two study periods for patients admitted with sepsis in the emergencies and hospitalized outside the ICU. A) Pathogens are distributed according to Gram stain or fungal species; B) Mixed infections are presented; C) Distribution of species of Gram (−) bacteria; and D) Distribution of species of Gram (+) cocci. Asterisks indicate statistical significances between the two study periods. CoNS: coagulase negative Staphylococcus spp.

Figure 3

Resistance rates of isolates of Escherichia coli and of Klebsiella pneumoniae of patients admitted with sepsis and hospitalized outside the ICU for the two study periods. Asterisks indicate statistical significances between the two study periods.

Figure 4

Distribution of bloodstream pathogens between the two study periods for patients with sepsis developing after ICU admission. A) Pathogens are distributed according to Gram stain or fungal species; B) Mixed infections are presented; C) Distribution of species of Gram (−) bacteria; and D) Distribution of species of Gram (+) cocci. Asterisks indicate statistical significances between the two study periods. CoNS: coagulase negative Staphylococcus spp.

Figure 5

Resistance rates of isolates of Klebsiella pneumoniae, of Acinetobacter baumannii and of Pseudomonas aeruginosa of patients developing sepsis after ICU admission of the two study periods.

Figure 6

Impact of de-escalation on final outcome. Kaplan Meier survival analysis was conducted comparing patients for which antimicrobials were de-escalated by the attending physicians (Yes, solid line) with those for which antimicrobials were not de-escalated by the attending physicians (No, dashed line) separately for the study period 2006–2009 (panel A) and for the study period 2010–2013 (panel C). P values refer to comparisons between patients under de-escalation and patients without de-escalation. Panels B (study period 2006–2009) and D (study period 2010–2013) refer to forward Cox regression analysis of the impact of de-escalation on the final outcome after adjustment for the presence of severe sepsis/shock, age, gender and for comorbid illnesses. CI: confidence intervals; HR: hazard ratio.