MONDAY, Sept. 14, 2026 (HealthDay News) — New research suggests that the blood pressure and heart rate guidelines doctors use to guide emergency treatment in children are misleading in cases of traumatic injury. 

These thresholds for "hemodynamic instability" — the inability of the circulatory system to get blood to organs — may be different for children with traumatic injuries versus healthy children, researchers wrote Sept. 9 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,” explained study senior author Dr. Zain Hashmi. He's an assistant professor of trauma and acute care surgery at the University of Alabama at Birmingham.

Blood pressure and heart rate guidelines are often used by doctors to decide when to start resuscitation treatments, including blood transfusions, Hashmi said in a news release. However, the values used in children were not developed specifically for trauma patients and may not accurately reflect when the risk of death begins to rise in injured children, he added. 

The study analyzed information from a national database on trauma care. Researchers looked at cases of over 233,000 injured children ages 1 to 15 who were treated at participating trauma centers between 2018 and 2023.

Researchers tracked values for blood pressure, heart rate and shock index (a combination of heart rate plus blood pressure) that had been most strongly associated with death in these cases.

They then compared those threshold numbers with current pediatric thresholds used in clinical practice.

Thresholds for low blood pressure readings that were linked to an increased death risk among the kids in the study were 18% higher than thresholds used in general practice, the study found.

That means that many kids who could be in danger of dying after trauma are overlooked based on current thresholds, the team warned.

While just 2% of patients in the study would have met thresholds for dangerously low blood pressure, the "real" number could be about 7%, Hashmi's group estimated.

“Injured children are treated in emergency departments across the country, not only at pediatric trauma centers,” noted lead author Dr. Chandler Annesi, a general surgery resident at the University of Alabama at Birmingham. “Providing clinicians with more accurate thresholds for recognizing instability could help them identify children at risk earlier and monitor them more closely.”

Combining readings of heart rate and blood pressure may be crucial when assessing young patients after trauma, she added.

Annesi said the new data shows just how quickly an injured child’s condition can worsen after trauma.

"Often, the pediatric literature suggests that a high heart rate is the first sign that a patient needs help," she said. "But by the time children get to the trauma bay, they may be past the point when they only exhibit a high heart rate, so we need to pay attention to their blood pressure as well."

More information

There's more on pediatric trauma guidelines at the Pediatric Trauma Society.

SOURCE: American College of Surgeons, news release, Sept. 9, 2026