Who Owns the Patent on My Baby’s Ductus Arteriosus?

Contributed by: Grant Schmalz, Pharm.D. Candidate

UMKC School of Pharmacy

Text Box: What is a Patent Ductus Arteriosus? A patent ductus arteriosus (PDA) is a normal part of the circulation of a fetus. The ductus arteriosus is a patent (open) vessel that connects the aorta (carries blood to the body) and the pulmonary artery (carries blood to the lungs). Before birth the baby’s lungs are not functional and the mother supplies the oxygen. The ductus arteriosus prevents high blood flow to the lungs while they are not functioning. With the baby’s first breath, the lungs expand filling with air and become the source of oxygen for the baby. The ductus arteriosus usually closes within the first 2-3 days of life. Occasionally the ductus arteriosus will remain open and this is referred to as a patent (open) ductus arteriosus. What are the signs and symptoms of a patent ductus arteriosus? The symptoms usually depend on the size of the ductus and how much blood flow it carries. The blood typically flows through the ductus arteriosus from the aorta to the pulmonary artery. The amount of additional blood reaching the lungs depends on the size of the ductus itself. If it is very small, for example when the ductus muscles did not close the vessel completely, little extra blood can squeeze through the PDA. In this case, the child will have no symptoms at all, and will appear to be perfectly healthy. If the PDA is large, an enormous amount of additional blood may "flood" the lungs. This extra blood flow into the lungs can overload the lungs and put an additional burden on the heart to pump this extra blood. These children are often quite sick in the first few days or weeks of life, with symptoms of poor feeding, poor weight gain, constant sweating, hard breathing and fast heart rate.

Text Box: How is patent ductus arteriosus diagnosed? The presence of the characteristic murmur along with symptoms of heart failure in a premature infant most frequently leads to the diagnosis of patent ductus arteriosus. The chest X-ray will show an enlarged heart and evidence of an excessive amount of blood flow to the lungs. An echocardiogram is performed to confirm the diagnosis. This will demonstrate the size of the ductus arteriosus and will demonstrate if the heart chambers have become enlarged due to the extra blood flow. In older children the chest x-ray is typically normal and the echocardiogram is required for diagnosis. What is the treatment for a patent ductus arteriosus? In premature and newborn infants additional time is allowed to let the vessel close on its own unless symptoms are severe and medical or surgical closure is required. Beyond the newborn period the vessel will probably never close on its own. Newborns can be treated with non-steroidal anti-inflammatory drugs (NSAIDs) such as indomethacin or ibuprofen. These medications cause the muscle in the patent ductus arteriosus to constrict and promote closure. Medical treatment is about 80% successful. Older infants and children will require surgical closure to either suture the ductus closed or plug it. Complications with any of the treatments are low depending on how ill the child is prior to treatment. Summary The diagnosis of Patent Ductus Arteriosus (PDA) is relatively common, affecting 1 in 2,000 children. While the majority of children do not have symp

Text Box: toms, the risks are nonetheless real. For women in their third trimester it is important to avoid NSAIDs to prevent premature closure of the patent ductus arteriosus. It is comforting for parents to know that no matter which technique is employed for treating this problem of their child's heart, after closure of the PDA, the circulation is normal, and the child will have a normal heart with no further risks for the remainder of a normal life. For more information contact the American Heart Association at www.americanheart.org.