New tests monitor brain health during children's heart surgery

A new monitoring method and blood test may provide early warnings when a child's brain isn't getting enough blood during heart surgery, according to new research presented during the American Heart Association's Emerging Science Series webinar.

Brain injury occurs in 30 percent to 70 percent of infants and children undergoing repair of congenital heart defects. A is a heart abnormality present at birth. Out of 1,000 in the United States, about 8 babies will have some kind of heart defect.

Previously, there has been no way to detect brain injury during surgery as it happens. This research was a multi-center observational pilot study to evaluate the feasibility of new monitoring strategies in a high-risk population of children with .

Unlike other organs, the brain can automatically adjust blood vessel size to keep blood flow constant when blood pressure changes. Researchers developed the "hemoglobin volume index," a non-invasive monitoring technique to assess changes in the brain arteries. This monitoring technique allowed them to determine the lowest pressure before automatic adjustment was compromised. Researchers compared patient blood pressures with blood levels of glial fibrillary acidic protein (GFAP), an indicator of .

In 61 children (aged one week to 17 years) undergoing surgery, researchers found that:

  • A lower limit of pressure autoregulation or LLA could be identified in 85 percent of the children and varied widely between patients; meaning that 85 percent are at risk of brain hypoperfusion.
  • Both the hemoglobin volume index and GFAP became abnormal when the childrens' heart and lung function was taken over by cardiopulmonary bypass during surgery, with the worst readings during rewarming, indicating the period of highest risk for the child undergoing heart surgery;
  • The more time spent below LLA was associated with some increase in GFAP, suggesting a link between periods of decreased blood flow autoregulation and decreased brain blood flow and brain injury.
"Because the autoregulatory changes occurred almost concurrently with signs of , we may have a real-time measure where we can detect when injury is occurring and modify how we are managing the patients, for example being more aggressive with controlling blood pressure," said R. Blaine Easley, M.D., lead author and associate professor in anesthesiology and pediatrics at Baylor college of Medicine in Houston.

The next step is a multi-center study that will correlate intra-operative test results with MRI changes and neurodevelopmental outcomes in the 18 months after surgery.

add to favorites email to friend print save as pdf

Related Stories

No drop in IQ seen after bypass for child heart surgery

Nov 10, 2008

The use of cardiopulmonary bypass does not cause short-term neurological problems in children and teenagers after surgery for less complex heart defects, according to pediatric researchers. The new finding contrasts favorably ...

Recommended for you

Neonatal vitamin K refusal tied to nonimmunization

Aug 20, 2014

(HealthDay)—While neonatal vitamin K refusal is rare, parents who refuse vitamin K are less likely to immunize their child, according to a study published online Aug. 18 in Pediatrics.

Teen sleeplessness piles on risk for obesity

Aug 20, 2014

Teenagers who don't get enough sleep may wake up to worse consequences than nodding off during chemistry class. According to new research, risk of being obese by age 21 was 20 percent higher among 16-year-olds who got less ...

Researchers show economic disparities impact infant health

Aug 20, 2014

Women who are poor experience higher cortisol levels in pregnancy and give birth to infants with elevated levels of the stress hormone, putting them at greater risk for serious disease later in life, according to a new research ...

User comments