Verigene® blood culture nucleic acid test identifies microorganisms and resistance genes faster than traditional methods. Despite its proven accuracy, the possibility of false results or co-infections exists, necessitating result interpretation in context of other clinical findings. Given the paucity of data describing patient characteristics related to antibiotic intervention rate, the study aim was to evaluate antibiotic interventions in ICU and non-ICU patients. The hypothesis is that interventions are performed less frequently in ICU patients due to greater concern for co-infections and acuity of comorbidities.
Multi-center, retrospective, observational cohort study conducted in adult patients admitted with positive blood culture. Patients were excluded if cultures were polymicrobial or not identified by Verigene®. Intervention was defined as any change to empiric antibiotics to achieve narrowest effective coverage between the time of Verigene® and final culture results.
One-hundred thirty patients were included (64 ICU vs 66 non-ICU) accounting for 70 and 71 cultures, respectively. Age, weight and antibiotic allergies were similar between groups. There was no difference in intervention rate between ICU and non-ICU patients (15.7 vs 18.3%, p=0.852). More coagulase-negative Staphylococcus, S. aureus and vancomycin-resistant Enterococcus were detected in ICU patients. Device accuracy was 99%. Comparing patients who did and did not receive intervention, more antibiotic-induced nephrotoxicity occurred in those with no intervention (8.3 vs 29.9%, p=0.053); vancomycin had highest association. History of resistant organisms (OR 3.613; CI 1.055-12.368; P=0.041) was identified as a risk factor for no intervention multivariate logistic regression. Blood and non-blood cultures rarely grew the same organism.
Overall intervention rate was similar between ICU and non-ICU patients. The low intervention rates could be a result of synonymous empiric and narrowest effective coverage for some organisms. Clinicians were less likely to intervene if patients had history of resistant organisms. The utility of preliminary culture results with accompanying molecular diagnostics was similar between ICU and non-ICU patients.
J. Winter, None
C. Droege, None
M. Foertsch, None
E. Mueller, None