Final answer:
The condition where pulmonary blood vessels remain constricted in hypoxemic babies is known as patent ductus arteriosus (PDA), a congenital heart defect that can cause respiratory issues and other symptoms if not treated.
Step-by-step explanation:
The condition in which the pulmonary blood vessels in babies who were hypoxemic around the time of birth may remain constricted is known as patent ductus arteriosus (PDA). This is a congenital heart defect where the ductus arteriosus fails to close after birth.
In a normal fetal heart, the ductus arteriosus diverts blood away from the lungs and into the aorta due to the fact that the developing fetus does not use its own lungs for oxygenation. However, postnatally, this passageway is supposed to close so that blood can flow to the now functioning lungs to be oxygenated.
If this does not occur, it can lead to increased pulmonary pressure and respiratory difficulties, as well as other symptoms including dyspnea, tachycardia, enlarged heart, widened pulse pressure, and poor weight gain.
Treatments for PDA could involve surgical procedures like ligation or the insertion of platinum coils or specialized mesh, alongside the use of nonsteroidal anti-inflammatory drugs to encourage closure of the ductus arteriosus.