AVM

Finally found out what's been causing the blue arm and other assorted symptoms Zachary has been experiencing the past few weeks.  It's called an Arteriovenous Malformation, or AVM, for short.

It was hard to follow the explanation we got from the docs but here goes.  One of the arteries in his right upper chest sprang a leak sometime ago (probably because it was nicked by one of the central lines he had in the past) and established a connection, referred to as a shunt or fistula, with a nearby vein.  Then the capillaries in the area intertwined themselves around the whole thing creating a tangled mess of blood vessels.

The result:  oxygenated blood coming from his heart is not going to his arm like it is supposed to.  Instead it is taking a short cut through the connection between the artery and vein and is being shuttled right back to his heart, making his heart work harder than it should.  The concerns are twofold.  First, the vessels could weaken and start bleeding badly.  Second, his heart could be jeopardized because it is trying to compensate for the diverted blood flow.  Both would be life threatening. 

AVMs are more common in the brain, though they can appear anywhere in the organs, torso, or limbs.  Many people who have them are asymptomatic, in which case surgical intervention may be eschewed.  But action is indicated in most cases when symptoms are present, as in Zachary's case. 

Aside from his arm turning blue, it gets cold and swells, and his heart rate has increased by about 20 beats per minute, indicating increased strain on his heart.  And he's been a little uncoordinated the past week or so, stumbling around and struggling to keep his balance.   These symptoms are not unusual for people with AVMs, apparently.

His cardiologist has consulted with a vascular surgeon, who is devising a plan of attack, which will involve one or more procedures to alleviate the problem.  He'll have to be in the cardiac ICU as a precaution following the surgery, which I think is just hospital protocol and not because of specific concerns.

We're sad, of course, that our little guy has to go through more invasive tinkering with his insides.  And we're also frustrated that this might delay the mid-August sleep study that could allow us to start weaning the vent.  Seems like we keep taking two steps forward and one, or more, back. 

Should know in the next day or so what the plan will be.