The role of antimicrobials in the treatment of sepsis and critical illness-related bacterial infections: examination of the evidence

OBJECTIVE

To appraise the evidence behind the Surviving Sepsis Campaign Guidelines on antimicrobial therapy in sepsis and evaluate relevant literature in small animal veterinary critical care.

DATA SOURCE

Electronic searches using MEDLINE and EMBASE databases.

HUMAN DATA SYNTHESIS

Current recommendations are to administer appropriate antimicrobials within 1 hour of a diagnosis of severe sepsis or septic shock. Evidence is supportive of this recommendation in septic shock but the evidence is less compelling in milder forms of critical illness-related infections. It is unclear when the administration of appropriate antimicrobials is most beneficial and when it should be considered essential. Evidence supports shorter courses of antimicrobial therapy for many infections seen in the critical care unit with the biomarkers procalcitonin and C-reactive protein helpful in guiding the duration of therapy.

VETERINARY DATA SYNTHESIS

Current evidence is lacking to support the use of early and aggressive use of antimicrobials in all patients with critical illness-related bacterial infections. Two studies failed to demonstrate improved survival in patients with pulmonary or abdominal infections administered appropriate vs inappropriate empirical antimicrobials. One study failed to show an improved survival when dogs with abdominal infections were administered antimicrobials within 1 hour vs 6 hours of diagnosis of infection. Information regarding ideal duration of antimicrobial therapy and use of biomarkers to guide therapy is currently lacking.

CONCLUSION

Clinicians should aim to administer early and appropriate antimicrobials; however, the impact this will have on patient outcome remains uncertain. The ability to administer early and appropriate antimicrobials may be considered a measure of the quality of medical practice rather than a prognostic indicator.

Impact of appropriate empirical antimicrobial therapy on outcome of dogs with septic peritonitis

OBJECTIVE

To determine whether appropriate empirical antimicrobial therapy influenced survival in dogs with septic peritonitis.

DESIGN

Retrospective case series (2003-2011).

SETTING

University teaching hospital.

ANIMALS

Eighty-six dogs with cytological confirmation or positive bacterial culture of abdominal sepsis and subsequent surgical intervention.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Forty-nine of 86 dogs (57%) survived to hospital discharge. Thirty-seven of 86 dogs were classified as having ''abdominal infection,'' 31/86 as ''severe sepsis,'' and the remaining 18/86 as in ''septic shock.'' Mortality was greatest in the ''septic shock'' category (94%). Empirical antimicrobial treatments were appropriate in 41/78 dogs (52.6%). Appropriateness was not associated with treatment outcome overall or when compared between sepsis severity groups. Antimicrobials had been given in the 30 days before admission in 63/86 (73.3%) dogs. Prior therapy with antimicrobials showed no association with outcome (P = 0.512) but was associated with subsequent inappropriate empirical antimicrobial selection (P = 0.031). Recent abdominal surgery was associated with subsequent inappropriate empirical antimicrobial selection (P = 0.021).

CONCLUSIONS

In this population, appropriateness of empirical antimicrobial choice was not associated with survival to discharge. Previous antimicrobial administration or abdominal surgery was associated with subsequent inappropriate empirical antimicrobial selection.