A daily challenge for the multidisciplinary team in intensive care units (ICUs) is balancing broad-spectrum antibiotics with the appropriate empirical antibiotic therapy.
To establish the carbapenem-resistant Gram-negative bacilli screening cultures predictives values.
We conducted a retrospective study. We included patients admitted to the intensive care unit for at least 48 hours. We measured carbapenem-resistant negative and positive predictive values, sensitivity, and specificity in Gram-negative bacilli screening cultures.
We included 331 infected patients. We found high negative predictive values in Gram-negative carbapenem-resistant bacilli screening cultures: A. baumannii: 95% (91- 97); P. aeruginosa: 86% (82 - 92); Enterobacteriaceae spp.: 93% (89 - 95). On the other hand, low positive predictive values were found: A. baumannii 27% (15 – 43); P. aeruginosa 35% (15 – 43) and Enterobacteriaceae spp.: 22% (9 – 42). In the same way, screening culture's sensibility was 41% (24 – 61) for A. baumannii, 27% (16 – 41) for P. aeruginosa, and 21% (8 – 41) for Enterobacteriaceae spp. The specificity for A. baumannii was 89% (85 – 93).
If uncolonized patients, screening cultures effectively predict that patients will rarely be infected with carbapenem-resistant Gram-negative bacilli. Despite previous colonization being an infection factor risk by these pathogens, most colonized patients, when they developed an infection, were not caused by carbapenem-resistant Gram-negative bacilli. So, screening cultures can be an important tool for pharmacist intervention. Thus, we suggest starting empirical antibiotics aimed at carbapenems-resistant Gram-negative bacilli only in cases where infected patients previously colonized by these pathogens with signs of organ dysfunction.