Study sheds light on risk of life-threatening blood clots in hospitalized children

December 12, 2013

Life-threatening blood clots occur so rarely in children that the condition, known as venous thromboembolism (VTE), is often not on pediatricians' mental radar screens -- an absence that can lead to woefully delayed recognition and treatment.

Now findings of a Johns Hopkins Children's Center study, published online Dec. 12 in The Journal of Pediatrics, may help clinicians determine which hospitalized children are at greatest risk of VTE and require vigilant monitoring or preemptive treatment with anticlotting medications.

The investigators say that in the absence of much-needed pediatric guidelines on VTE prophylaxis in children, the study findings can help guide clinical decision-making for certain categories of hospitalized patients who are at a disproportionately high risk for developing clots.

Such categories include older teens and young adults, those with multiple medical conditions, patients with central venous catheters and those with cardiac and renal disease.

The study, which analyzed 15 years' worth of medical records of thousands of children treated at the Johns Hopkins Children's Center between 1994 and 2009, found 270 cases of VTE in more than 90,000 pediatric admissions. Despite the miniscule overall VTE rate, clotting risk loomed large in several groups, with older age and the presence of multiple medical conditions carrying the highest risk of VTE. Young adults between the ages of 18 and 21 were eight times more likely to develop a clot than younger children between the ages of 2 and 9. Teens, ages 14 to 17, had a four-fold rate of VTEs, compared with younger children. In addition, teenage girls and young women were nearly two times as likely to develop a clot as males the same age. Children with four or more medical conditions were four times more likely to develop VTE than others.

Other factors that appeared to fuel clotting risk were the presence of central venous catheters, recent surgery and traumatic injuries. Half of the 238 children who developed clots had a central venous catheter, and 40 percent of clots developed in children who'd undergone recent surgeries. When clots developed in infants, they did so predominantly in patients with congenital heart defects. By contrast, clots in trauma patients tended to develop mostly in older teens and young adults.

The research team says that children who fall into more than one category should be monitored extra vigilantly for signs suggestive of a clot.

"Are we saying that every kid with more than one risk factor should be on prophylactic treatment? Absolutely not," says study lead investigator Cliff Takemoto, M.D., a pediatric hematologist at the Johns Hopkins Children's Center. "What we are saying, however, is that we, as clinicians, should take a closer look at each and every patient with multiple risk factors and gauge cumulative risk -- if the chance of clotting appears high enough, then treatment is certainly reasonable."

Considered somewhat of a clinical enigma in children, VTEs have been long recognized as a major threat in hospitalized and immobilized adults. This well-established risk is at the heart of guidelines that call for preventive anticlotting therapy in adults with certain conditions. But because clotting risk in children is so poorly understood, the researchers say, pediatricians often find themselves at a loss when trying to decide whom to treat and when. In addition, because anticlotting medications can cause harmful side effects including excess bleeding and low platelet counts physicians are understandably hesitant to use them preemptively in children.

"Blood clots in children are quite rare, yet when they do occur they can be life-threatening, so treatment decisions often pose an intricate dilemma for clinicians who have to weigh the small risk of a potentially fatal condition against the possibility of serious harm that can come from prophylactic treatment," Takemoto says.

Findings of the new study add to a growing body of research on clotting risk in children. Another recent Johns Hopkins study, published Oct. 30 in JAMA Surgery, found that VTE risk among children with traumatic injuries rose dramatically in those 16 and older. Patients in that age group were nearly four times more likely to develop life-threatening blood clots than their younger counterparts.

Usually arising in the veins of the legs, blood clots can break away and travel to the lungs where they lodge in the arteries, obstruct breathing and cause a potentially fatal condition known as pulmonary embolism. Signs of deep vein clots include pain, tenderness and swelling at the site of clot formation, usually in the legs or arms. Symptoms suggestive of pulmonary embolism include chest pain, rapid and labored breathing, spitting blood and fainting.
-end-
Other investigators involved in research were Sajeet Sohi, M.D.; Kruti Desai, M.D.; Raman Bharaj, M.D.; Anuj Khanna, M.D.; Susan McFarland, M.D.; Sybil Klaus, M.D.; Alia Irshand, M.D.; Neil Goldenberg, M.D., Ph.D.; J.J. Strouse, M.D., Ph.D.; and Michael Streiff, M.D.; all of Johns Hopkins.

Related on the Web:

Study: Anti-Clotting Drugs Rarely Needed in Children with Big-Bone Fractures

http://www.hopkinschildrens.org/Study-Anti-Clotting-Drugs-Rarely-Needed-in-Children-with-Big-Bone-Fractures.aspx

JAMA Surgery: Venous Thromboembolism after Trauma: When Do Children Become Adults?

http://archsurg.jamanetwork.com/article.aspx?articleid=1764700&resultClick=1

Johns Hopkins Medicine

Related Blood Clots Articles from Brightsurf:

New cause of COVID-19 blood clots identified
A new study reveals that COVID-19 triggers production of antibodies circulating through the blood, causing clots in people hospitalized with the disease.

Children who take steroids at increased risk for diabetes, high blood pressure, blood clots
Children who take oral steroids to treat asthma or autoimmune diseases have an increased risk of diabetes, high blood pressure, and blood clots, according to Rutgers researchers.

COVID-19 may cause deadly blood clots
COVID-19 may increase the risk of blot cots in women who are pregnant or taking estrogen with birth control or hormone replacement therapy, according to a new manuscript published in the Endocrine Society's journal, Endocrinology.

New evidence for how blood clots may form in very ill COVID-19 patients
Neutrophil Extracellular Traps (NETs) have been implicated in causing excessive clotting in cancer patients.

Researchers find new way to detect blood clots
Researchers in the Department of Biomedical Engineering at Texas A&M University are working on an entirely new way to detect blood clots, especially in pediatric patients.

High rate of blood clots in COVID-19
COVID-19 is associated with a high incidence of venous thromboembolism, blood clots in the venous circulation, according to a study conducted by researchers at Brighton and Sussex Medical School (BSMS), UK.

New tool helps distinguish the cause of blood clots
A new tool using cutting-edge technology is able to distinguish different types of blood clots based on what caused them, according to a study published today in eLife.

Hookah smoke may be associated with increased risk of blood clots
In a new study conducted in mice, researchers found that tobacco smoke from a hookah caused blood to function abnormally and be more likely to clot and quickly form blood clots.

Reducing the risk of blood clots in artificial heart valves
People with mechanical heart valves need blood thinners on a daily basis, because they have a higher risk of blood clots and stroke.

New study provides insight into the mechanisms of blood clots in cancer patients
Researchers have identified a potential new signaling pathway that may help further the understanding of blood clot formation in cancer patients and ultimately help prevent this complication from occurring.

Read More: Blood Clots News and Blood Clots Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.