Nav: Home

Low-cost blood test good predictor of increased bleeding risk in pediatric trauma patients

September 28, 2015

A team of researchers from the Trauma Program at Children's Hospital Los Angeles conclude that an admission hematocrit provides a reliable screening test for identifying pediatric patients who are at an increased risk of bleeding after injury. Their retrospective review of approximately 1,340 trauma patients, ages 0 to 17 years, will be published in the Journal of Trauma and Acute Care Surgery and is currently available on PubMed at

Hematocrit is a blood test that measures the percentage of the volume of whole blood that is made up of red blood cells. This measurement depends on the number and size of red blood cells. Contrary to earlier medical teachings, adult trauma studies have shown that a drop in hematocrit can occur immediately after injury - predicting ongoing occult, or non-obvious, blood loss. To date, the use of hematocrit in triaging bleeding pediatric trauma patients had not been investigated.

In examining the patient medical records of all patients who presented to the level 1 pediatric trauma center at CHLA between 2005 and 2013, the researchers found that an admission hematocrit of ?35 was able to identify children who required an intervention - either transfusion or operation - for bleeding, up to 67 hours after arrival.

Unintentional injury from trauma is the leading cause of death in children older than one year of age. Because young children can be far more difficult to assess clinically than adults, identifying their injuries and assessing blood loss in these patients is more challenging, requiring resources including advanced imaging, inpatient observation and serial blood tests. Identifying pediatric intra-abdominal injury (IAI) is especially difficult, according to the CHLA researchers. Computed tomography (CT) scans are often used to evaluate patients, but these involve radiation exposure and increased cost.

"A quick and cost-effective measure, such as admission hematocrit, to identify pediatric patients who are at a high risk for bleeding could provide a critical improvement in optimizing care for children, while reducing costs," said principal investigator Christopher P. Gayer, MD, PhD, FAAP, FACS, of Trauma Attending in the Division of Pediatric Surgery at CHLA.

The results of the study showed a significant difference in admission hematocrit between patients who subsequently required a transfusion and those who did not. The cutoff figure of ?35 had a 94 percent sensitivity, 77 percent specificity and nearly 100 percent negative predictive value. This led the researchers to conclude that use of this cutoff provides a reliable screening tool, due to its low false negative rate and high specificity for identifying those at increased risk of bleeding.

"Admission hematocrit can be done rapidly in the trauma bay, is relatively inexpensive, causes minimal harm and can aid in critical decision-making and rapid identification of occult bleeding. Our results show that a hematocrit level of less than 35% on admission predicts a greater likelihood for the need of transfusion in pediatric blunt trauma patients," said first author Jamie Golden, MD, a research fellow at CHLA.

The physicians noted that while a doctor's concern in the face of clinical signs of hemorrhagic shock should always take priority over lab data, a repeat hematocrit can be quickly and easily performed if clinically indicated. They added that the results of their study, conducted retrospectively at a single site, require validation in a prospective, multicenter study.
Additional contributors to the study include Avafia Dossa, MD, MS, Catherine J. Goodhue, MN, and Jeffrey S. Upperman, MD, FAAP, FACS, all of Children's Hospital Los Angeles.

About Children's Hospital Los Angeles

Children's Hospital Los Angeles has been named the best children's hospital in California and among the top 10 in the nation for clinical excellence with its selection to the prestigious U.S. News & World Report Honor Roll. Children's Hospital is home to The Saban Research Institute, one of the largest and most productive pediatric research facilities in the United States. Children's Hospital is also one of America's premier teaching hospitals through its affiliation since 1932 with the Keck School of Medicine of the University of Southern California. For more information, visit Follow us on Twitter, Facebook, YouTube and LinkedIn, or visit our blog at

Children's Hospital Los Angeles

Related Red Blood Cells Articles:

Red blood cell donor pregnancy history not tied to mortality after transfusion
A new study has found that the sex or pregnancy history of red blood cell donors does not influence the risk of death among patients who receive their blood.
How sickled red blood cells stick to blood vessels
An MIT study describes how sickled red blood cells get stuck in tiny blood vessels of patients with sickle-cell disease.
Red-blood-cell 'hitchhikers' offer new way to transport drugs to specific targets
A new drug-delivery technology which uses red blood cells to shuttle nano-scale drug carriers, called RBC-hitchhiking, has been found in animal models to dramatically increase the concentration of drugs ferried precisely to selected organs,
Novel gene in red blood cells may help adult newts regenerate limbs
Adult newts can repeatedly regenerate body parts. Researchers from Japan, including the University of Tsukuba, and the University of Daytona, have identified Newtic1, a gene that is expressed in clumps of red blood cells in the circulating blood.
Bristol researchers use gene editing to improve red blood cell transfusion compatibility
Synthetic biologists at the University of Bristol have succeeded in generating laboratory-made red blood cells with rare blood group types that could one day be used to help patients who cannot be matched with donor blood.
More Red Blood Cells News and Red Blood Cells Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...