Written by Doug Wallace
Spoon Feed
This retrospective study found that radiographic pneumonia was diagnosed on follow-up imaging in 11% of children with an initially negative chest x-ray (CXR). Certain clinical signs (hypoxemia, tachypnea, dehydration) were more common in those who later developed pneumonia.
X-ray vision is still reliable (with caveats)
This 10-year retrospective review of 240 pediatric ED visits for suspected pneumonia with an initially negative CXR found that 27 (11%) were later diagnosed with radiographic pneumonia on repeat imaging. Of note, nearly 10,000 patients were included in the initial review, with only 240 receiving a follow-up CXR, suggesting loss to follow-up may have introduced ascertainment bias into this study.
Those with delayed pneumonia were notably more likely to have hypoxemia (37% vs 13%), tachypnea (44% vs 15%), and dehydration (41% vs 20%) at presentation. About half were admitted, and a few had complications like effusions requiring thoracentesis.
Importantly, no missed consolidations were found on initial CXRs in a reviewed subgroup, and CXR had a negative predictive value of 99.7% on the index visit.
How does this change my practice?
This study reaffirms that a normal CXR in the ED in a nontoxic pediatric patient is largely reassuring, though I’ll keep a closer eye on kids with early presentation and red flags like hypoxemia, tachypnea, or dehydration.
Editor’s note: Thanks for feedback from Dr. Leighton at UCSF. To clarify, the overall rate of subsequent pneumonia was 0.27% (27/9957). 11% of those who returned and had a subsequent CXR (27/240) had pneumonia. ~Clay Smith
Source
Risk of Subsequent Pneumonia After a Negative Chest Radiograph in the ED. Pediatrics. 2025 May 1;155(5):e2024069829. doi: 10.1542/peds.2024-069829. PMID: 40189217
