Claeys KC, et al. - The infection characteristics, antibiotic consumption, and clinical and economic outcomes of patients with Gram-negative (GN) lower respiratory tract infections (LRTIs) treated in intensive care units (ICUs) were described. Researchers recognized frequent identification of drug-resistant pathogens and inappropriate empiric GN therapy in nearly 50% of cases. Inappropriate therapy resulted in increased lengths of stay and higher associated costs of care.

Methods

• A retrospective, observational, cross-sectional study was performed of adult patients treated in ICUs at two large academic medical centers in metropolitan Detroit, Michigan, from October 2013 to October 2015.
• Patients must have had CDC-defined LRTI caused by a GN pathogen during ICU stay to meet the inclusion criteria.
• Researchers assessed minimum inhibitory concentrations for key antimicrobial agents of available Pseudomonas aeruginosa isolates.

Results

• Researchers recognoized 472 patients, primarily from the community (346, 73.3%), treated in medical ICUs (272, 57.6%).
• They observed common occurrence of clinically defined pneumonia (264, 55.9%).
• From index respiratory cultures, 619 GN organisms were identified: P. aeruginosa was common (224, 36.2%), with 21.6% of these isolates being multidrug resistant.
• The most frequent empiric GN therapies were cefepime (213, 45.1%) and piperacillin/tazobactam (174, 36.8%).
• In 44.6% of cases, empiric GN therapy was inappropriate.
• The most common reason for inappropriateness was lack of in vitro susceptibility (80.1%).
• Inappropriate empiric GN therapy resulted in longer overall stay, which translated to a median total cost of care of $79,800 (interquartile range $48,775 to $129,600) vs $68,000 (interquartile range $38,400 to $116,175), p=0.013.
• They observed no differences regarding clinical failure (31.5% vs 30.0%, p=0.912) and in-hospital all-cause mortality (26.4% vs 25.9%, p=0.814).