Correlation between respiratory colonization with gram-negative bacteria and development of gram-negative bacterial infection after cardiac surgery.

This pilot, observational study involving 286 patients who underwent cardiac surgery found that patients who had endotracheal colonization with gram-negative bacteria at 1 week after surgery were more likely to develop subsequent infection compared to those without colonization (8 of 23 vs. 4 of 40; relative risk 2.3 [95% confidence interval, 1.3-4.1; P value <.05]).