Impact of Organism Reporting from Endotracheal Aspirate Cultures on Antimicrobial Prescribing Practices in Mechanically Ventilated Pediatric Patients

Abstract

Endotracheal aspirate cultures (EACs) help diagnose lower respiratory tract infections in mechanically ventilated patients but are limited by contamination with normal microbiota and variation in laboratory reporting. Increased use of EACs is associated with increased antimicrobial prescribing, but the impact of microbiology reporting on prescribing practices is unclear. This study was a retrospective analysis of EACs from mechanically ventilated patients at Children’s Hospital Colorado (CHCO) admitted between 1 January 2019 and 31 December 2019. Chart review was performed to collect all culture and Gram stain components, as well as antibiotic use directed to organisms in culture. Reporting concordance was determined for each organism using American Society for Microbiology guidelines.

So tell me… does this tracheal aspirate culture indicate “infection” or “colonization”?

“…11,12 Finally, in the postanalytic period, adhering to reporting guidelines or modifying microbiology reports from respiratory cultures may help reduce unnecessary antibiotic prescribing. 6,13 Given the findings of this study and others, we encourage providers not to overly rely on the results of TA culture and to use them judiciously. We see no indication for routine testing in…”

“…Balancing the need for antibiotics with the risk of antibiotic resistance is important, and despite some utility in the use of organism quantity and predominance for sorting out colonizing organisms from pathogens, the presence of polymorphonuclear cells on Gram stain and the growth of an organism that grew previously may be unhelpful 5 Additionally, reporting organisms from TA cultures may contribute to excessive antibiotic use, regardless of whether an organism is pathogenic or commensal. In a recent single‐center pediatric study of mechanically ventilated patients, overreporting of organisms from TA culture (identifying and reporting organisms considered commensal flora) was associated with significantly more antibiotic use 6 …”

“…During the analytic period, screening methods can be used to ensure that only acceptable specimens are tested, improving the clinical utility of the results and reducing specimen volume and associated costs 11,12 . Finally, in the postanalytic period, adhering to reporting guidelines or modifying microbiology reports from respiratory cultures may help reduce unnecessary antibiotic prescribing 6,13 …”

“…In a recent single-center pediatric study of mechanically ventilated patients, overreporting of organisms from TA culture (identifying and reporting organisms considered commensal flora) was associated with significantly more antibiotic use. 6 Despite the potential impact of TA culture results on prescribing behavior, providers have the best of intentions. Clinicians hope to treat their patients proactively and effectively before a further respiratory decline occurs.…”

Repeat Tracheal Aspirate Cultures: A Port in the Storm or a Sinking Ship?*

“…Second, while improved diagnostic tests for bacterial VAI are undoubtedly urgently needed, diagnostic test stewardship targeting TACs offers a promising strategy to limit VAP overdiagnosis and unnecessary antibiotic use. The clinical microbiology laboratory is a critical partner in optimizing these efforts, which may have significant impacts on antibiotic use given data suggesting that excess antibiotic use is associated with identifying and reporting organisms not supported by recommendations (15). Finally, future work should focus on defining the clinical scenarios where this testing has maximum utility and defining both the patient and clinician factors driving TAC utilization.…”