Empiric antimicrobial therapy in critical illness: results of a surgical infection society survey.
BACKGROUND
Antibiotics are prescribed commonly in the intensive care unit (ICU). Often, therapy is initiated empirically; practice patterns are not well characterized. We documented approaches to empiric antibiotic therapy among members of the Surgical Infection Society (SIS).


METHODS
We sent a scenario-based questionnaire to all SIS members. The hypothetical cases addressed empiric broad-spectrum therapy for a patient with pyrexia and leukocytosis and the use of vancomycin for central venous catheter infection.


RESULTS
The 113 respondents were primarily surgeons (96%) with a university-based practice (92%). Most attended in the ICU (72%), and they had practiced for 14 +/- 8 years. Whereas 63% of the respondents identified overuse of antibiotics as a problem in their ICU, only 19% said inadequate treatment of infection was a concern. For a febrile patient with negative cultures who was receiving antibiotics, estimates of the likelihood of infection increased across the three scenarios as the degree of organ failure increased (p < 0.0001; chi-square test). Deteriorating organ function was associated with a decision to broaden empiric therapy (58% vs. 33%; p < 0.0001) and to initiate anti-fungal therapy (27% vs. 9%; p < 0.0001) rather than to stop antibiotics and re-culture (15% vs. 51%; p < 0.0001). There was considerable variability in management strategy across the scenarios: Even in the face of organ dysfunction, 58% of physicians would add or change empiric therapy, whereas 30% would not. For each scenario, 23 to 25 antibiotic regimens were designated as optimal therapy. Only 45% of the respondents would initiate empiric vancomycin for suspected central line infection. Variability in approach was not explained by critical care practice, academic position, or country.


CONCLUSIONS
Clinical deterioration is a strong determinant of a decision to initiate or broaden empiric antibiotic therapy during critical illness. The substantial variability in approach suggests a state of clinical equipoise that calls for more rigorous evaluation through a randomized controlled trial.
Aarts
Mary-Anne W
MA
Department of Surgery, University of Toronto, Toronto, Ontario, Canada.
Granton
John
J
Cook
Deborah J
DJ
Bohnen
John M A
JM
Marshall
John C
JC
D000890:Anti-Infective Agents / Q000627:therapeutic use*; D016638:Critical Illness / Q000628:therapy*; D005334:Fever / Q000188:drug therapy; D013502:General Surgery; D019538:Health Care Surveys; D006801:Humans; D007362:Intensive Care Units; D007964:Leukocytosis / Q000188:drug therapy; D009102:Multiple Organ Failure / Q000188:drug therapy; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D012955:Societies, Medical; D014640:Vancomycin / Q000627:therapeutic use
D000890:Anti-Infective Agents; D014640:Vancomycin