Febrile Infant — Summary of Pathway Updates Adapted from AAP Guidelines 2021 — Clinical Pathway: Emergency Department and Inpatient

Febrile Infant Clinical Pathway — Emergency Department and Inpatient

Summary of Pathway Updates Adapted from AAP Guidelines 2021

Background:

This document summarizes key changes and rationale based on the AAP Clinical Practice Guideline: Evaluation and Management of Well-Appearing Febrile Infants   , published in August 2021.

  1. Updated age-based algorithms have been divided into three groups to help guide evaluation and management: 1) 0-21 days old, 2) 22-28 days old, and 3) 29-56 days old. Increasing evidence suggests a lower risk of invasive bacterial infection (IBI: bacteremia and/or meningitis) in the 4th week of life compared to the first 3 weeks and more closely mirrors the risk in the 2nd month of life. For this reason, 22-28 day old infants have been classified as a separate group.
  2. Historically, CBC, ANC and band count have been used in clinical prediction models to assess risk of IBI in febrile young infants (FYI). However, procalcitonin (PCT) has emerged as the most accurate independent predictor of IBI, so we do not recommend use of abnormal WBC and band count for risk stratification. For this reason, if PCT testing is available, we recommend use of PCT and ANC to risk stratify and guide management for FYI 22-56 days old. However, if PCT is unavailable, an abnormal ANC or CRP or a temperature >38.5°C are considered IMs associated with increased risk for IBI. Please see pathway algorithm to guide evaluation and management of these infants.
  3. Routine LP is no longer recommended for well-appearing 22-28 day old FYI with normal urinalysis and normal inflammatory markers. For these infants, we recommend admission for observation without antimicrobial therapy. If 1 or more inflammatory markers are abnormal or there is an abnormal urinalysis, we recommend LP, antimicrobial therapy, and admission.

Per the 2021 AAP guidelines, for infants 29-56 days old:

  • Obtaining CSF if any IM is abnormal (with or without abnormal UA) is a “Weak recommendation”
  • “Data are unavailable comparing prevalence of bacterial meningitis in IM-positive versus IM-negative infants”
  • “Individual IMs are seldom sensitive or specific for detecting bacteremia or meningitis. However, individual values that are exceedingly high or low or finding several abnormal IMs should be considered in decision-making.”
    Procalcitonin is considered most sensitive and specific for detecting IBI followed by CRP and ANC.

Prevalence of IBI by Age

Age in Days Bacteremia Bacterial Meningitis
8-21 3.9-5% 0.5-1.3%
22-28 1.6-5% 0.4-0.6%
29-60 1.1-2.2% 0.12-0.32%