Pulmonary Hypoplasia

00:00 Switching gears, let's talk a little bit about pulmonary hypoplasia which is a slightly different problem than surfactant deficiency. In this case, the baby has not developed the lungs appropriately while in utero. And there's a famous thing you should know about that is pretty high yield on the test which is the Potter sequence. I want to go through this with you carefully. Remember that the primary source of amniotic fluid inside the mother is the baby's urine. There are other tissues that makes some of the fluid such as skin and even lungs, but the urine is the primary source. So, if a child has agenesis of the kidneys and they're not making adequate urine, this will result in anuria in utero. That lack of fluid or amniotic fluid in the mother will in turn result in a decreased pressure of the fluid that is inside their lungs. Remember this is a closed system. As a result of that decreased pressure, the lungs will undergo agenesis and this child will have poorly developed lungs or pulmonary hypoplasia. So, before birth, we can make the diagnosis by noting decreased amniotic fluid levels or oligohydramnios or we may notice decreased fetal movements because the baby is literally pinned in place inside the uterus. And those are diagnosed before birth. Flipside, after birth, the baby may have apnea, the baby may have severe respiratory distress, the baby may develop a pneumothorax as they're trying to open their lungs but the lung is coming along with the chest wall creating a pneumothorax. The child may also have the original problem, the renal mass or the enlarged bladder from say severe posterior urethral valves. Anything that's causing the urine from not coming out. And, there is a typical facies appearance. It's easy to think of it as just simply the baby is so constricted, but their facies are abnormal. So these children may have Potter's facies as well and skeletal abnormalities having grown and developed in this fluid-deficient environment.

02:25 Those are ways we can diagnose these after birth.