CDH FAQ

I feel, quite often, in writing this blog that I don't do a very good job of explaining what's going on.  I assume everyone who reads this has spent unhealthy amounts of time perusing medical journals about CDH, as I have.  This is an attempt to explain some things in better detail.  Lord help me, I hope I get all this correct.

1.  WHAT IS CONGENITAL DIAPHRAGMATIC HERNIA? (CDH)
CDH is a birth defect that affects 1 out of every 2500 babies.  It occurs when the diaphragm either does not form at all or does not close, leaving a hole through which digestive organs can travel into the chest cavity.  The national survival rate for CDH babies hovers somewhere between 50 and 60%
2.  WHY DID THIS HAPPEN TO PARKER?
Nobody knows.  There are many ongoing research projects trying to pin down what causes a CDH.  All that is known is that something happens between 7 and 12 weeks gestation that stops the diaphragm from closing.  Thus far, no definitive answers as to genetics, heredity, or environmental factors have been found.  It is just a "short circuit" type of thing.  It's not my fault as his mother, and it's not his fault as a baby.

3.  WHY IS IT SO SERIOUS?
Looking at the drawing above does a pretty good job of explaining that.  In utero, the baby's heart and lung development are compromised by the organs taking up prime real estate in the chest cavity.  CDH also frequently occurs with other birth defects-- chromosomal anomalies, heart defects, etc.  It can be a sign that there are many things wrong with the baby.  It can also, as in our case, be a completely isolated defect not linked to anything.  We had an amniocentesis to make sure.

4.  WHAT DO YOU DO TO FIX IT?
The short answer to this is to have a surgeon shove everything back into it's correct location and stitch up the hole.

5.  THAT SURE SOUNDS EASY.
Yep.  Unfortunately, it's not.  CDH babies are born with severely compromised respiratory and digestive systems.  Step one, before repair surgery can even be discussed, is to be sure the baby is stable enough to withstand surgery.  A large determining factor is the heart's ability to pump blood into the lungs for oxygenating the body.  In utero, this process is unnecessary.  Upon a baby's birth, many factors have to line up just right to get the heart and lungs working in sync.  CDH babies have extra hurdles to get to that stage.  Post op, the situation can get hairy as well-- just because the hole is repaired doesn't mean the baby can magically breathe.  Or eat.

6.  WHAT CAN YOU DO BEFORE PARKER'S BORN?
Not a darn thing.  Go to the doctor 5000 times to make sure no other complications pop up.  Stay pregnant as long as possible.  Despite all of the doctor visits prenatally, there are no guarantees or concrete prognoses that can be made until the medical team sees Parker in person.

7.  WHAT HAPPENS WHEN HE IS BORN?
He will be immediately sedated and put on a ventilator.  As they won't know how well his lungs can function, they will err on the side of caution and breathe for him until they get a better idea as to what is going on.  At no point do they want Parker deprived of oxygen.  If he is able to breathe better than anticipated, the ventilator can be scaled back.  If he is unable to breathe as well as expected, the ventilator will make sure he is getting much needed oxygen.  After he proves stable in the heart and lung department (i.e. tolerating the ventilator and maintaining good heart function), repair surgery will be done.

8.  WHAT IF HE'S NOT PROVING STABLE IN THE FIRST FEW DAYS?
There are lots of medications and ventilation techniques that will be tried.  If those do not help, he will be put on an ECMO machine.  ECMO is the reason he has to venture to Egleston instead of staying with me at Northside-- very few hospitals in the country have ECMO, and it's vitally important that Parker be as close as possible to an ECMO machine if he needs it. He might wind up needing it after his repair surgery, if complications with his heart and/or lungs arise.

9.  WHAT ON EARTH IS ECMO?
ECMO (extracorporeal membrane oxygenation) is a super-scary last resort intervention for very sick babies.  If Parker is unable, even with ventilation and medication, to oxygenate himself, he will deteriorate quickly.  An ECMO machine is basically a heart/lung bypass machine that pulls the blood from his body, oxygenates it, and pushes it back in.  It's used to give a baby's heart and lungs time to rest and hopefully strengthen while the machine does the hard work.  It has GREATLY increased the survival of CDH babies, but it has its drawbacks. Being on ECMO for more than 3 weeks can severely damage a baby's brain and body.  Blood clots can form inside the machine, which can spell disaster just as blood clots do for normal people.
The bottom line with ECMO is that you really, really don't want to wind up on it.  If you do, chances are good that it's going to help the baby recover, it's just going to add some speedbumps along the way.

10.  SO AFTER SURGERY COMES...
A series of baby steps out the NICU door.  Step one-- demonstrate ability of heart to function appropriately.  Step two-- demonstrate ability of lungs to expand, grow, and start functioning on their own.  Step three-- breathe without ventilation.  Step four-- suffer through Baby Rehab as medications are knocked down and withdrawn.  Step five-- demonstrate ability of newly rearranged digestive tract to tolerate feeding.  Step six-- convince all doctors (it seems like there are 40) that you can leave.

It's a long road (average 8 week NICU stay).  It's a rollercoaster (these babies go from fantastic to frightening in seconds).  It's something we certainly had never heard of and knew nothing about until December 21, 2011.  What I do know, now, is that there is a FANTASTIC group of parents out there who have been through this and come out on the other side.  Because of their stories, we have hope!