Risk of Subsequent Pneumonia After a Negative Chest Radiograph in the ED.

Area of Science:

• Pediatric Emergency Medicine
• Radiology
• Infectious Disease

Background:

• Chest radiography (CXR) is a common tool for diagnosing pneumonia.
• Concerns exist regarding the timing of radiographic findings relative to clinical symptoms.
• The diagnostic reliability of CXR in pediatric pneumonia requires further investigation.

Purpose of the Study:

• To determine the incidence of radiographic pneumonia in children with an initially normal CXR.
• To identify characteristics of pediatric patients who develop pneumonia after a negative initial CXR.

Main Methods:

• Retrospective cohort study conducted over 10 years in a tertiary pediatric emergency department.
• Included children under 21 with suspected pneumonia, a normal initial CXR, and a follow-up CXR within 14 days.
• Excluded children with chronic conditions or ICU admission.

Main Results:

• Out of 9957 children with suspected pneumonia and a normal initial CXR, 240 had a follow-up CXR within 14 days.
• Radiographic pneumonia developed in 27 children (11% of those with a second CXR).
• Tachypnea, hypoxemia, and dehydration were identified as predictors of developing radiographic pneumonia.

Conclusions:

• The occurrence of radiographic pneumonia after a normal CXR is infrequent in the emergency department setting.
• CXR is a reliable tool for excluding pneumonia in the ED.
• Increased clinical caution is advised for children presenting with specific clinical features, such as tachypnea, hypoxemia, or dehydration.