Kids with congenital heart disease at high risk from harmful toxins in blood

Washington: A research by a team at Imperial College London has indicated that babies and toddlers with congenital heart disease are at an increased risk of having harmful toxins in their blood.

Congenital heart disease is one of the most common types of birth defect, affecting about 1 in every 145 births. Some abnormalities are minor and do not require treatment, but many babies and young children have to undergo surgery to correct the defect.

The gut usually acts as a barrier that protects the body from toxins, Dr Nazima Pathan, the lead author of the study from the National Heart and Lung Institute at Imperial College London, said.

However, our study suggests that in some babies with congenital heart disease, the gut isnt able to do this job properly. These babies are often small and undernourished, and the heart defect can mean that the blood supply to the gut is abnormal.

On top of this they have to cope with the trauma of surgery and our study suggests that all these factors can affect the protective barrier function of the gut, Pathan said.

Pathan and her team measured the levels of endotoxins in 40 children requiring surgery for congenital heart disease, admitted to the paediatric intensive care unit at Royal Brompton Hospital, where Pathan is a paediatric consultant. The children ranged in age between 2 and 46 months.

The results showed that even before surgery, over a fifth of children had higher than normal levels of endotoxin, and levels rose after surgery. Overall 27.5 percent of the children had raised endotoxin levels after surgery.

The highest endotoxin levels were measured in small children and those whose heart defects resulted in compromised blood supply to the gut.

Importantly, children with high endotoxin levels showed more signs of organ dysfunction and tended to spend longer in intensive care.

The children may have! been ex posed to bacterial toxins during surgery. However, the levels of toxins in the blood continued to rise in the days after surgery, suggesting that bacteria in the gut were the main source.

We were surprised at how common endotoxaemia was in these children and how strongly endotoxin levels correlated with poor clinical outcomes, Pathan added.

The study has been published in the American Journal of Respiratory and Critical Care Medicine.