C-reactive protein diagnostic value for bacterial infections in the paediatric emergency department setting

Area of Science:

• Pediatric Emergency Medicine
• Clinical Chemistry
• Infectious Disease Diagnostics

Background:

• C-reactive protein (CRP) is a key biomarker for assessing bacterial infection probability.
• Empiric antibiotic treatment decisions in pediatric emergency rooms often rely on CRP levels.
• Understanding the diagnostic accuracy of CRP in this setting is crucial.

Purpose of the Study:

• To evaluate the relationship between C-reactive protein (CRP) levels and bacterial infection in pediatric emergency room patients.
• To determine the sensitivity and specificity of various CRP thresholds for diagnosing bacterial infections.

Main Methods:

• Retrospective cohort study of 13,092 pediatric emergency room cases.
• Calculation of relative risks (RRs) for CRP levels against demographic, clinical, and diagnostic parameters.
• Assessment of sensitivity and specificity for CRP levels of 2, 5, 7, and 10 mg/dL.

Main Results:

• Elevated CRP levels correlated with fever, leucocytosis, hospitalization, and bacterial infection diagnosis.
• Lower CRP levels were associated with younger age; no association found with gender, ethnicity, hypoxemia, or neutrophilia.
• CRP ≥5 mg/dL demonstrated high specificity (>80%) for bacterial disease, while sensitivity declined (<50%) at this threshold.

Conclusions:

• CRP levels ≥5 mg/dL offer high specificity for bacterial infections, justifying empiric antibiotic initiation.
• The low sensitivity of CRP across tested levels suggests it may not be suitable for withholding empiric antibiotic treatment.
• CRP is a valuable tool but should be interpreted alongside clinical context in pediatric emergency settings.