A study of more than 233,000 injured children found that blood pressure linked with a higher risk of death was higher than current pediatric standards.
Researchers found the biggest differences among children ages 1 and 2.
The findings could help doctors recognize circulatory problems sooner, but more research is needed before new thresholds can be adopted.
When a child is seriously injured, doctors closely monitor vital signs such as blood pressure and heart rate. These measurements can help medical teams determine whether the body is getting enough blood flow to vital organs and whether treatments such as blood transfusions may be needed.
But researchers behind a new study say the blood pressure levels commonly used to identify dangerously low blood pressure in children may not be designed with injured children in mind. Current standards are based largely on reference values from healthy children.
That could mean some injured children are already experiencing dangerous circulatory problems before their blood pressure falls low enough to meet the usual definition of hypotension, according to the study published in the Journal of the American College of Surgeons.
“Recognizing hemodynamic instability is fundamental in trauma care because these vital signs tell us when a child may be at increased risk of death or complications and when we may need to intervene,” Zain G. Hashmi, MD, FACS, an assistant professor of trauma and acute care surgery at the University of Alabama at Birmingham (UAB), and senior author of the study, said in a news release.
“Blood pressure and heart rate often help determine when clinicians should begin resuscitative interventions, including a blood transfusion. However, commonly-used pediatric reference values were not developed specifically for trauma patients and may not accurately reflect when the risk of death begins to rise in injured children.”
Researchers looked at more than 230,000 children
The researchers conducted a retrospective study using data from the American College of Surgeons Trauma Quality Improvement Program. They examined records from 233,490 children between ages 1 and 15 who were treated for traumatic injuries at participating trauma centers between 2018 and 2023.
The team looked at three measurements: systolic blood pressure, heart rate, and something called the shock index. The shock index combines heart rate and systolic blood pressure into one measurement.
Researchers then used statistical analyses to identify age-specific values associated with death and compared those numbers with existing pediatric standards, including Pediatric Advanced Life Support (PALS) definitions for low blood pressure and the Pediatric Age-adjusted Shock Index (SIPA).
Higher blood pressure levels were linked to increased risk
The blood pressure levels associated with mortality were consistently 15 to 30 mmHg higher than the PALS thresholds currently used to define hypotension. Researchers said that the difference was about 18%.
Using the study's trauma-specific thresholds, about 7% of injured children would have been classified as having low blood pressure, compared with less than 2% under the current thresholds. The biggest differences between the study's findings and existing standards occurred among children ages 1 and 2.
The researchers also found that heart rate and shock index can provide useful information about a child's condition. The study's shock-index thresholds closely matched existing SIPA values, providing additional support for using that measurement alongside blood pressure.
The findings don't immediately change how injured children are treated. The researchers said additional studies are needed to determine whether higher blood pressure thresholds would actually improve outcomes. The study also relied on data from participating trauma centers, so its findings may not represent every U.S. hospital.
“Trauma care is improved by research that challenges the status quo and defines clear parameters for organizing the most efficient, effective trauma care possible,” said Jeffrey D. Kerby, MD, PhD, FACS, medical director of ACS Trauma Education, director of the Division of Trauma and Acute Care Surgery at UAB, and a co-author of the JACS paper.
“This research provides an opportunity to use a data-driven approach to improve treatment for the most critically injured children.”