Risk factors for mortality in patients with nosocomial Gram-negative rod bacteremia

The percentage of hospital-acquired bloodstream infections associated with Gram-negative bacilles has decreased during last decade but it is still a major cause of morbidity and mortality.

The aim of this study was to determine the outcome of Gram-negative rod (GNR) bacteremia, which is an important clinical problem with high mortality rates, and the risk factors for GNR related mortality in our Clinic.

During the study period, 520 episodes of bacteremia were detected in 411 patients. Only patients with GNR bacteremia in blood cultures were included in the study (n = 197). Among 197 patients fulfilling study criteria, GNR were grown in 239 samples.

Escherichia coli (n = 97, 40.5%), Klebsiella pneumoniae (n = 54, 22.5%), Pseudomonas aeruginosa (n= 24, 10%), Acinetobacter baumannii (n = 24, 10%) were the most commonly isolated bacteria. The most frequently identified infection sources of bacteremia were pneumonia (n = 35, 17.7%), catheter-related infections (n = 24, 12.2%), urinary tract infections (n = 20, 10%). In multivariate analysis, it was found that the GNR bacteremia mortality risk increased in patients treated in intensive care units (ICU) (OR: 0.2, p = 0.03) and patients with ventilatory support (OR: 20.8, p = 0.05).

In clinical practice of the hospital settings, efforts should concentrate on preventive measures for nosocomial infections since pneumonia, catheter-related infections, and urinary infections appear to be the most frequent causes of secondary bacteremia.