Editor’s Note: Dr. Julie Evans (she/her) is a resident physician in pediatrics at the University of Virginia. She is interested in general pediatrics and global health. -Rachel Y. Moon, MD, Associate Editor, Digital Media, Pediatrics
Pneumonia, an infection of the lungs, is a common pediatric diagnosis in the emergency department (ED), clinic, and hospital. The “gold standard,” or best diagnostic test, is chest x-ray (CXR), though pneumonia does also have typical findings on lung exam that clinicians may pick up.
There has been rising concern that CXR findings lag behind the clinical symptoms of pneumonia, meaning CXR may not be as reliable to diagnose pneumonia as we think. Dr. Hirsch and colleagues from Boston Children’s Hospital and Tufts University tackle this in their article entitled “Risk of Subsequent Pneumonia after a Negative Chest X-Ray in the ED” being early released in Pediatrics (10.1542/peds.2024-069829).
The authors completed a retrospective cohort study in one pediatric ED over 10 years (2012–2021). About 30,000 children under the age of 21 with fever or respiratory illness had a CXR to evaluate for pneumonia during the study period. After excluding those with chronic medical conditions, ICU admission, prior ED visit in 30 days for similar symptoms, and those diagnosed with pneumonia at first visit, data from a cohort of 9,957 children were analyzed.
Of these patients, 240 (2.4%) had a repeat CXR within 14 days, and 27 of the 240 (11.3%; 0.27% of total cohort) had developed radiographic pneumonia on repeat CXR. Of the 27 with pneumonia, 13 were hospitalized, 6 had parapneumonic effusion, and 2 required thoracentesis (drainage of fluid from the chest).
At the end of their analysis, the authors concluded that pediatricians can rely on initial CXR to exclude pneumonia, with a negative predictive value (how correct a negative result is) of 99.7%.
They also found that children were more likely to develop pneumonia later on if the following were present at the initial visit:
- Dehydration
- Tachypnea
- Hypoxemia
- History of asthma
Yet, even with these characteristics, it was still rare for pneumonia to be seen on repeat CXR.
Pediatricians can rely on CXR to exclude a diagnosis of pneumonia, even when clinically suspected.
