Anesthesia Drug May Better Protect Newborn Brains During Heart Surgery

Researchers at The Children's Hospital of Philadelphia used desflurane, an anesthesia gas, on piglets that underwent a low-flow type of cardiopulmonary bypass at one week of age. The animals that received desflurane were better able to walk and feed, and had less injury to brain tissue, compared to piglets that received liquid anesthesia drugs, a combination of fentanyl and droperidol.

Animals in the desflurane group also showed fewer abnormal heart rhythms during cardiopulmonary bypass, suggesting that the drug may protect heart function as well.

"This study adds to growing evidence that this type of anesthetic protects the brain and nervous system during heart surgery," said Andreas W. Loepke, M.D., Ph.D., a pediatric anesthesiologist at The Children's Hospital of Philadelphia, and lead author of the study published in the December issue of Anesthesiology.

As survival rates have increased for infant heart surgeries, physicians have been able to turn more attention to improving quality of life in survivors. The very techniques that make open heart surgery possible also may contribute to neurological complications. Cardiopulmonary bypass (CPB) reroutes a patient's blood through a heart-lung machine while surgeons repair complex heart defects. During low-flow CPB, blood flow to the brain is reduced to 10 percent of normal, as opposed to deep hypothermic circulatory arrest (DHCA), in which blood flow is completely stopped.

Even though low-flow CPB seems to show some advantages over DHCA in neurological outcomes, following either procedure, children may suffer decreased levels of intelligence and reduced motor and language skills, compared to children who did not undergo open-heart surgery.

The researchers remain uncertain about the process by which desflurane improved neurologic outcomes in their study, although they speculate that it may decrease the amount and effects of deleterious amino acids in the brain. The current study builds on previous animal research by the Children's Hospital team, which showed neurological benefits to using desflurane during DHCA.

Approximately 40,000 babies are born in the United States every year with cardiovascular defects. About half of these children must undergo open-heart surgery with CPB before their first birthday. Dr. Loepke added that, "If results in humans parallel our results in animal studies, desflurane or similar anesthetics could contribute to clinical improvements for children with heart conditions."

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Co-authors with Dr. Loepke, all from The Children's Hospital of Philadelphia, were Margaret A. Priestley, M.D., Steven E. Schultz, M.D., John McCann, B.S., Jeffrey Golden, M.D., and C. Dean Kurth, M.D. The study was supported by Baxter PPI, of New Providence, N.J., which manufactures desflurane.

The Cardiac Center at The Children's Hospital of Philadelphia offers comprehensive care for children with congenital or acquired heart disease. It performs over 1000 pediatric cardiothoracic surgeries per year, making it one of the largest such programs in the world.

Founded in 1855 as the nation's first pediatric hospital, The Children's Hospital of Philadelphia is ranked today as the best pediatric hospital in the nation by a comprehensive Child magazine survey. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals and pioneering major research initiatives, Children's Hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country, ranking second in National Institutes of Health funding. For more information, visit www.chop.edu.