Risk factors for ICU-acquired imipenem-resistant Gram-negative bacterial infections.

Intensive care units (ICUs) are high-risk areas for infections caused by antibiotic-resistant bacteria. This study investigated the risk factors for ICU-acquired imipenem-resistant Gram-negative infections. It was conducted prospectively in three surgical ICUs and one medical ICU from April to December 2002. ICU-acquired Gram-negative infections were found in 128 patients. Of these, 42 had imipenem-resistant and 86 had imipenem-sensitive Gram-negative bacteria as the cause of infection. According to the univariate analysis results, hospital stay before ICU admission, hospitalization period before ICU admission, length of ICU stay, surgical ICU stay, surgical operation and previous antibiotic use were significant risk factors for the acquisition of imipenem-resistant infections. In the multivariate analysis, length of ICU stay, surgical operation and previous carbapenem use were independently associated with imipenem resistance.