Antibiotic management of suspected nosocomial ICU-acquired infection: does prolonged empiric therapy improve outcome?
OBJECTIVE
To characterize empiric antibiotic use in patients with suspected nosocomial ICU-acquired infections (NI), and determine the impact of prolonged therapy in the absence of infection.


METHODS
Multicenter prospective cohort, with eight medical-surgical ICUs in North America and Europe.


METHODS
195 patients with suspected NI.


METHODS
The diagnosis of NI was adjudicated by a blinded Clinical Evaluation Committee using retrospective review of clinical, radiological, and culture data.


RESULTS
Empiric antibiotics were prescribed for 143 of 195 (73.3%) patients with suspected NI; only 39 of 195 (20.0%) were adjudicated as being infected. Infection rates were similar in patients who did (26 of 143, 18.2%), or did not (13 of 52, 25.0%) receive empiric therapy (p = 0.3). Empiric antibiotics were continued for more than 4 days in 56 of 95 (59.0%) patients without adjudicated NI. Factors associated with continued empiric therapy were increased age (p = 0.02), ongoing SIRS (p = 0.03), and hospital (p = 0.004). Patients without NI who received empiric antibiotics for longer than 4 days had increased 28-day mortality (18 of 56, 32.1%), compared with those whose antibiotics were discontinued (3 of 39, 7.7%; OR = 5.7, 95% CI 1.5-20.9, p = 0.005). When the influence of age, admission diagnosis, vasopressor use, and multiple organ dysfunction was controlled by multivariable analysis, prolonged empiric therapy was not independently associated with mortality (OR = 3.8, 95% CI 0.9-15.5, p = 0.07).


CONCLUSIONS
Empiric antibiotics were initiated four times more often than NI was confirmed, and frequently continued in the absence of infection. We found no evidence that prolonged use of empiric antibiotics improved outcome for ICU patients, but rather a suggestion that the practice may be harmful.
Aarts
Mary-Anne W
MA
University of Toronto, Interdepartmental Division of Critical Care Medicine and the Department of Surgery, Toronto, Canada.
Brun-Buisson
Christian
C
Cook
Deborah J
DJ
Kumar
Anand
A
Opal
Steven
S
Rocker
Graeme
G
Smith
Terry
T
Vincent
Jean-Louis
JL
Marshall
John C
JC
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D003428:Cross Infection / Q000188:drug therapy*; D019049:Developed Countries; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies
D000900:Anti-Bacterial Agents