Standard pediatric blood pressure thresholds miss early trauma warning signs

Blood pressure thresholds commonly used to identify dangerously unstable vital signs in children may not signal trouble soon enough after a traumatic injury, according to a national study of more than 230,000 pediatric trauma patients. The findings suggest clinicians may need to recognize and respond to signs of circulatory instability at higher blood pressure levels than current pediatric reference values indicate.

In the Journal of the American College of Surgeons (JACS) study, researchers used a large national trauma database to identify blood pressure and heart rate values signifying hemodynamic instability, which occurs when the circulatory system cannot maintain adequate blood flow to vital organs, and compared them with previously known thresholds. 

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, assistant professor of trauma and acute care surgery, University of Alabama at Birmingham (UAB), and senior author of the study

“Blood pressure and heart rate often help determine when clinicians should begin resuscitative interventions, including a blood transfusion,” Dr. Hashmi added. “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.”

Study details

Using the American College of Surgeons Trauma Quality Improvement Program (TQIP) database, researchers analyzed 233,490 injured children ages 1 to 15 treated at participating trauma centers between 2018 and 2023. They identified the blood pressure, heart rate, and shock index values most strongly associated with death and compared them with pediatric thresholds currently used in clinical practice. Shock index combines heart rate and systolic blood pressure into a single measure.

When researchers compared the trauma-derived thresholds with current Pediatric Advanced Life Support (PALS) and age-adjusted pediatric shock index (SIPA) reference values, they found:

• The blood pressure thresholds associated with increased mortality risk were 15 to 30 mmHg higher, an approximately 18% difference, than PALS values commonly used to define hypotension. Using the trauma-derived thresholds, approximately 7% of injured children would have been classified as hypotensive, compared with less than 2% under current thresholds.
• Age-adjusted heart rate and shock index can also help identify children at increased risk of hemodynamic instability and death. Previously defined thresholds closely aligned with those identified in the study, reinforcing the value of considering heart rate together with systolic blood pressure during early trauma resuscitation, the authors said

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

“This research shows just how quickly an injured child’s condition can worsen after trauma,” she added. “Often, the pediatric literature suggests that a high heart rate is the first sign that a patient needs help. 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.”

The study is limited to the TQIP database, which draws data from participating trauma centers and may not reflect all U.S hospitals, particularly those in rural or community hospital settings.

The authors said the study is a step toward refining the thresholds used to guide treatment of pediatric trauma patients. Future research will need to determine whether revised values can improve outcomes for critically injured children.

“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.”

Additional study co-authors are Pawan Acharya, MSPH, PhD; Russell Griffin, PhD; Robert T. Russell, MD, MPH, FACS; and John B. Holcomb, MD, FACS.