step_by_step_febrile_infant: Step-by-Step Approach for Febrile Infants

In cliot: Clinical Indices and Outcomes Tools

Step-by-Step Approach for Febrile Infants

Description

Calculates the risk stratification for Invasive Bacterial Infection (IBI) in febrile infants (typically <= 90 days old) using the "Step-by-Step" approach. This sequential algorithm allows for the identification of low-risk infants who may be managed without lumbar puncture or antibiotics.

Usage

step_by_step_febrile_infant(age_days, ill_appearing, urinalysis_positive,
                            procalcitonin, crp_mg_l, absolute_neutrophil_count)

Arguments

age_days	Numeric. Age of the infant in days.
ill_appearing	Numeric (0 or 1). Is the infant ill-appearing? (1 = Yes). If Yes, the patient is automatically High Risk.
urinalysis_positive	Numeric (0 or 1). Is there leukocyturia (positive urinalysis)? (1 = Yes). If Yes, the patient is High Risk.
procalcitonin	Numeric. Serum Procalcitonin level in ng/mL. (>= 0.5 ng/mL indicates High Risk).
crp_mg_l	Numeric. C-Reactive Protein level in mg/L. (> 20 mg/L indicates Intermediate Risk if previous steps are negative).
absolute_neutrophil_count	Numeric. Absolute Neutrophil Count (ANC) in cells/mm^3. (> 10,000 indicates Intermediate Risk if previous steps are negative).

Value

A list containing:

Risk_Classification	The determined risk category (High Risk, Intermediate Risk, or Low Risk).
Recommendation	Clinical guidance based on the risk level.

References

Mintegi S, Bressan S, Gomez B, et al. Accuracy of a sequential approach to identify young febrile infants at low risk for invasive bacterial infection. Emerg Med J. 2014;31(e1):e19-24. doi:10.1136/emermed-2013-202449 Gomez B, Mintegi S, Bressan S, et al. Validation of the "Step-by-Step" Approach in the Management of Young Febrile Infants. Pediatrics. 2016;138(2). doi:10.1542/peds.2015-4381

Examples

# Example 1: Low Risk
# 45 days old, Well-appearing, Neg UA, PCT 0.1, CRP 5, ANC 4000
step_by_step_febrile_infant(45, 0, 0, 0.1, 5, 4000)

# Example 2: High Risk (Procalcitonin)
# 60 days old, Well-appearing, Neg UA, PCT 0.8, CRP 10, ANC 5000
step_by_step_febrile_infant(60, 0, 0, 0.8, 10, 5000)

# Example 3: Intermediate Risk (CRP)
# 50 days old, Well, Neg UA, PCT 0.2, CRP 30, ANC 5000
step_by_step_febrile_infant(50, 0, 0, 0.2, 30, 5000)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.