Written by Rebecca DiFabio and Ketan Patel
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Both of the AAP’s Guidelines on febrile, well-appearing infants aged 22-60 days old (PCT + ANC or Tmax + ANC + CRP) are excellent in ruling out invasive bacterial infection (IBI).
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It’s of the utmost importance to have a standardized approach to ruling out IBI in some of our smallest and most susceptible patients. In 2021, the AAP published guidelines on evaluating the febrile, well-appearing infant aged 8-60 days, with 3 separate algorithms further separated by age. The 22-60 day age group algorithm offered 2 risk stratification strategies: procalcitonin (PCT) + absolute neutrophil count (ANC) OR Tmax + ANC + CRP. Since not all centers have PCT, is the alternate strategy safe?
This retrospective, multicenter, secondary analysis validates the use of either AAP-recommended strategy for ruling out IBIs. Data from 12,846 infants were analyzed, showing that both strategies have high sensitivity (≥95%) and negative predictive value (≥99.8%) for detecting IBIs. PCT + ANC had the highest specificity (63.2% for infants aged 22-60 days), potentially reducing unnecessary lumbar punctures and hospitalizations. Only 4 of 12,846 included children would have been falsely categorized as low-risk. The results of this review are more broadly generalizable, as it included data from both children’s and general hospitals. As with all retrospective studies, there are limitations including incorrect categorization as well-appearing, and the reliance on documentation, which can be inaccurate.
How does this change my practice?
Having these guidelines to drive the workup of febrile children in this age group is so helpful, particularly given these results showing they can be applied to both children’s and non-children’s hospitals. Of course, gestalt and overall clinical impression is important and cannot be overlooked, but these guidelines will certainly be implemented in my practice.
Source
Diagnostic Performance of AAP-Recommended Inflammatory Markers in Febrile Infants Aged 60 Days or Younger. Pediatrics. 2025 Jan 1;155(1):e2024068856. doi: 10.1542/peds.2024-068856. PMID: 39636262
