Abstract & Commentary

Pediatric-Specific Antibiograms Improve Empiric Drug Selection

By Hal B. Jenson, MD, FAAP, Dean, Western Michigan University School of Medicine, Kalamazoo, Michigan, is Associate Editor for Infectious Disease Alert.

Dr. Jenson reports no financial relationships in this field of study.

Synopsis: Knowledge of pediatric-specific antimicrobial susceptibility data improves prescribing selections of empiric antibiotic treatment. Providers should advocate for availability of pediatric-specific antimicrobial susceptibility data wherever practical.

Source: Boggan JC, Navar-Boggan AM, Jhaveri R. Pediatric-specific antimicrobial susceptibility data and empiric antibiotic selection. Pediatrics 2012;130:e615-e622.

At Duke University Health System, a tertiary-care medical center that has traditionally provided aggregated antimicrobial susceptibility data from both adult and pediatric isolates, antibiograms for Escherichia coli isolates from children ≤12 years of age from July 2009 to September 2010 were developed and compared with antibiograms that combined adult and pediatric data. A total of 375 pediatric isolates were obtained from 327 patients. E. coli isolates from pediatric patients were more likely to be resistant to amoxicillin, amikacin and TMP-SMX and less likely be resistant to amoxicillin-clavulanate and ciprofloxacin then E. coli isolates from all age groups (P<0.0005).

A case-based survey of pediatric providers using two clinical vignettes — a three-month-old infant and a 12-year old-old child — with probable urinary tract infection was used to determine the impact of availability of pediatric-specific data on antibiotic selection. Providers responded to the clinical vignette survey under three circumstances: first with no antibiotic susceptibility data, then with aggregated pediatric and adult susceptibility data, and finally with pediatric-specific susceptibility data. Surveys were completed by 26 of 43 (61%) attending pediatricians and 49 of 92 (53%) pediatrics or medicine-pediatrics residents.

When no data was provided for the case of the 3-month-old, only 68.6% of providers selected an antibiotic with ≥80% in vitro efficacy against E. coli. This increased to 82.2% (P=0.08) when aggregated data was provided, and to 92.5% (P<0.01 compared to no data provided) when pediatric-specific data was provided. When pediatric-specific data was presented, providers were more likely to choose amoxicillin-clavulanate and less likely to choose TMP-SMX.

When no data was provided for the case of the 12-year-old, only 32.4% of providers selected an antibiotic with ≥ 80% in vitro efficacy against E. coli. This increased to 57.3% (P<0.01) when aggregated data was provided, and to 79.4% (P=0.01 compared to providing aggregated data) when pediatric-specific data was provided.

Commentary

Antimicrobial susceptibilities often differ significantly across the age spectrum as well as by the site of care (e.g., inpatient vs. outpatient). This study included a survey using case vignettes that demonstrated that knowledge of pediatric-specific data favorably altered provider empiric antibiotic selection.

Optimal empiric antibiotic selection in children should be based on age-specific antimicrobial susceptibility data, wherever possible, rather than aggregated data that combines pediatric and adult data. This study demonstrates that knowledge of pediatric antibiograms is an effective systematic step that facilitate providers choosing successful empiric antibiotic therapy in children. This should also minimize the adverse effects of antimicrobial use.

In many circumstances, there is minimal incremental work for the microbiology laboratory to report pediatric-specific data but significant benefit to optimal empiric antibiotic selection for children. Aggregating pediatric and adult data will likely continue to be necessary for infrequent isolates. For common isolates such as E. coli, pediatric providers should advocate with directors of clinical microbiology laboratories to provide availability of pediatric-specific antimicrobial susceptibility data wherever practical.