Photo by Vera Kratochvil
Researchers say they have discovered significant differences between blood clot structure in adults and newborns, a finding that could help us better understand the challenges in addressing post-operative bleeding in neonatal patients.
The researchers also found evidence to suggest the current standard of care for treating post-operative bleeding may pose an increased risk of thrombosis in newborns as compared to adults.
The team reported these findings in Anesthesiology.
“We knew that neonates—infants less than 1 month old—are more likely than adults to suffer from severe bleeding after heart surgery, which poses a variety of health risks,” said study author Ashley Brown, PhD, of the University of North Carolina at Chapel Hill.
“The current standard of care is to give neonatal patients blood products . . . derived from adult blood, but neonatal blood and adult blood aren’t the same. Many of the components involved in clotting in newborns have differing levels of activity, or effectiveness, compared to the same components in adults. Our goal was to better understand how clotting in neonates differs from that in adults so that we can move closer to developing more effective treatment strategies for these infants.”
The researchers’ hypothesis was that fibrinogen from neonates would form clots that are different from those formed by adult fibrinogen, and this proved correct. However, the team was surprised to find that fibrinogen from adults did not integrate well with fibrinogen from neonates.
To test their hypothesis, the researchers took samples of neonate fibrinogen and adult fibrinogen and compared clot formation. The team looked at clots formed solely of adult fibrinogen, clots formed solely of neonate fibrinogen, and clots made from a mixture of the two.
Neonate fibrinogen formed less dense, more fragile clots than adult fibrinogen. Likewise, a mixture of adult and neonate fibrinogen formed clots that were fragile and less dense, even if there was relatively little neonate fibrinogen in the mixture.
The researchers also evaluated how long it took these clots to dissolve. Clots of neonate fibrinogen dissolved about twice as quickly as clots formed from adult fibrinogen.
Clots formed from an adult and neonate fibrinogen mixture dissolved at approximately the same rate as adult-only clots, regardless of the percentage of neonate fibrinogen in the mixture.
“This suggests that using adult fibrinogen in neonatal patients may pose an increased risk of embolism or other adverse thrombotic events,” said study author Nina Guzzetta, MD, of the Emory University School of Medicine in Atlanta, Georgia.
“This work drives home that newborns are not just small adults, and we still have much to learn about clotting in neonates. It also tells us that there is a great deal of room for improvement in the current standard of care for post-operative bleeding in neonates.”
“We are investigating several approaches that may help address this problem, evaluating various modes of action,” Dr Brown added. “It is possible that we can use various external factors that promote clotting to stimulate the fibrinogen in neonates to form a denser clot.”
“We are investigating possible alternatives to help neonates form a better clot after major surgery without having to use adult fibrinogen. For example, we are investigating the use of synthetic platelet-like particles developed by our team to augment hemostasis . . . in blood samples collected from these patients.”
