UH Rainbow Team Identifies Risk Factors to Help Address the Growing Problem of VTE in Hospitalized Children

Study is first to link Venous Thromboembolism (VTE) to increased mortality in this population

Innovations in Pediatrics – Winter 2019

Researchers from University Hospitals Rainbow Babies & Children’s Hospitals have identified characteristics that put children hospitalized in the pediatric intensive care unit (PICU) at risk of developing venous thromboembolisms (VTEs). Plus, they’ve demonstrated that the risk of VTE in these patients is more widespread and serious than previously thought.

Sanjay Ahuja, MD

From 2001 to 2007, the incidence of VTE increased by 70 percent among inpatients in U.S. children’s hospitals, making the identification of risk factors a pressing need. In fact, the Children’s Hospitals’ Solutions for Patient Safety has identified VTE as the second-most preventable cause of harm for children who are hospitalized.

“We’re getting better at therapies, so more children are surviving to have this complication,” says UH Rainbow pediatric hematologist Sanjay P. Ahuja, MD, MSc, MBA, senior author of the study. “Because of that, we wanted to see if there were subgroups we could identify to find out which children in the PICU would develop a VTE in the hospital.”

For their analysis, the research team used the Virtual PICU database to identify more than 158,000 patients in pediatric intensive care units nationwide who had a central venous catheter (CVC). It’s estimated that up to 80 percent of VTEs in children are associated with critical illness or having a CVC. Of that population, a total of 1,602 pediatric patients had a VTE, yielding a rate of 103 per 10,000 children.

“This is higher than rates reported in prior studies that employed similar, large, multicenter databases,” Dr. Ahuja says. The group reported its results in the journal Thombosis Research and at the meetings of the American Society of Hematology and International Society on Thrombosis and Hemostasis.

Important risk factors for VTE among hospitalized children also emerged:

• Age less than 1 year
• Mechanical ventilation
• Diagnostic or therapeutic cardiac catheterization

“We also studied central venous lines separately,” Dr. Ahuja says. “We found that the PICC line had a pretty high incidence of developing VTE. The second highest was a femoral line. We also pitted tunneled vs. non-tunneled lines to see which was better. We found that non-tunneled lines (e.g. femoral line) had five times higher odds than the tunneled catheters (e.g. Mediport or Infusaport) of the patient developing a VTE.”

Importantly, the researchers also found a link between VTE and increased mortality in hospitalized children – the first study to show a statistically significant difference after controlling for other risk factors.

As a result of this work, the research team has created a web-based program that generates a score, stratifying patients at risk into categories.

“We call it the Cleveland score,” Dr. Ahuja says. “It’s an advanced statistical methodology that creates three risk categories – low, medium and high. In future studies, we will study whether patients who are in the high risk category should be put on prophylactic anticoagulation to help prevent thrombosis.”

Based on this research, we need to pay attention to children who are at the highest risk of developing VTE,” Dr. Ahuja adds. “We have proven that VTE can cause not only morbidity but also mortality. If you identify the subgroup at the highest risk, preventive measures should be focused on that population so that outcomes can be better.”

For more information about this research or the new Cleveland score, please email Peds.Innovations@UHhospitals.org.