Multicenter study advances blood clot screening in children - Children's National

When children arrive in the emergency department with symptoms that could signal a blood clot in the lungs, clinicians face a difficult balance: moving quickly to identify a potentially life-threatening condition while avoiding tests that may expose children to unnecessary radiation. A multicenter study published in The Lancet Respiratory Medicine with senior investigator Nathan Kuppermann, MD, MPH, executive vice president and chief academic officer of Children's National and director of the Children's National Research Institute, offers new evidence to help guide those decisions.

The findings, co-led by Wayne State University School of Medicine and Children's Hospital of Philadelphia, come from a study conducted across 21 pediatric emergency departments in the United States from 2020 to 2024. The study provides new evidence for evaluating children with symptoms that raise concern for pulmonary embolism (PE), while helping clinicians avoid CT scans when they may not be needed.

"Our study provides the strongest evidence to date that pulmonary embolism rule-out criteria for pediatrics, or PERC-Peds, is a safe rule-out tool for pulmonary embolism in children who are being evaluated for possible pulmonary embolism in the emergency department," said Dr. Kuppermann. "This simple bedside assessment can help doctors safely reduce unnecessary testing, lower radiation exposure and focus advanced imaging on the children who need it most."

The big picture

PE occurs when a blood clot travels to the lungs. Although it is less common in children than adults, it can be life-threatening if missed. At the same time, testing every child with chest pain or shortness of breath is not ideal because CT scans expose children to radiation and contrast dye, which carry their own risks.

The study enrolled 3,988 children with suspected PE and followed them for 45 days to identify those with the condition. Researchers found that 254 children, or 6.4%, had PE - a rate similar to that seen in adults being evaluated for PE.

The study also evaluated PERC-Peds, a decision rule that uses seven clinical features clinicians can assess at the bedside without laboratory or radiologic testing. PERC-Peds safely ruled out PE in children at very low risk: only one of 733 children in whom the rule predicted no PE was diagnosed with it within 45 days.

The results suggest that PERC-Peds can help emergency clinicians reduce unnecessary imaging while maintaining a very low chance of missing clinically important clots.

Why this matters

For pediatric emergency teams, the findings address a long-standing challenge: how to recognize a rare but dangerous condition without overusing tests that carry potential harm. Before the study, clinicians often had to rely on evidence developed in adults because large prospective pediatric studies had not been available.

The study also underscores that PE should remain on the list of possible diagnoses when children present with concerning symptoms. About 6% of children being evaluated for PE were ultimately diagnosed with a blood clot in the lungs or a deep vein thrombosis, a rate higher than many clinicians might expect.

By validating a bedside approach for children, the study gives clinicians stronger evidence to guide conversations with families, reduce low-value imaging and reserve advanced testing for children most likely to benefit.

You can read more about the study at Wayne State University School of Medicine.