But from everlasting to everlasting the LORD's love is with those who fear him and his righteousness with their children's children . . . Psalm 103:17

Saturday, September 1, 2012

What is a PDA anyway?

I think we've explained it in brief before, but I thought I might give some more details about a Patent Ductus Arteriosis.

This is such an awesome thing that God has built into our bodies.  When in the womb, a baby has no need to breathe, thus his lungs are not used for acquiring oxygen.  So God placed an artery "bridge" between the aorta and the pulmonary artery (large arteries coming out of the heart) to allow blood to shunt (flow) across from the pulmonary artery (the one going to the lungs) to the aorta (going to the rest of the body.  The lungs don't need the blood, so it flows through this bridge, called the ductus arteriosis, to the rest of the body.  When a baby is born, the oxygen supply from the placenta is cut off when the cord is cut.  Now he needs blood to go to the lungs via the pulmonary artery to allow oxygen to get to the lungs.  Shortly after the cord is cut, a chemical reaction takes place in the body that causes the ductus arteriosis (which is the size of the aorta and pulmonary artery) to shrink down and close off completely.  The process is not immediate, but takes place over a few weeks.  This closure allows the blood to flow to the appropriate parts of the body in appropriate volumes and pressures.  It then turns into a ligament which has no use beyond the womb, called the "ligamentum arteriosum."

In a premature baby of our babies' size, the chemical reaction often does not take place and the ductus arteriosis remains open.  "Patent" means "open", thus "patent ductus arteriosis."  The problem with this situation is that too much blood now goes to the lungs, being pumped from the aorta, which has higher pressure, through the ductus arteriosis into the pulmonary artery and into the lungs.  This extra blood, which is already oxegynated, takes the place of the blood needing the oxygen and causes a build-up of fluid in the lungs, among other problems.

The medicine "indomethacin" tries to do the work of the chemical reaction and close the artery.  Even when it closes, though, it can reopen, which has happened some with our babies.  The longer they get from birth, the less effective the medication becomes.  That is why Grace is going to need the surgery.  The procedure is called a "ligation."  The surgeon will put a metal clip on the unnecessary artery to close off the extra blood flow to the lungs.  It is a common procedure, but nonetheless serious surgery.

Grace is scheduled for the surgery on Tuesday sometime.  

Here is a picture of the heart and the ductus arteriosis.  

Class dismissed.


Gavin, Carrie, Isaac, Will, David, Marcie, Seth, & Grace Jones

Gavin, Carrie, Isaac, Will, David, Marcie, Seth, & Grace Jones

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