Cascade

Today Matt got called in to work, so I started the day with packing a diaper bag, a medical binder bag, a lunch, water bottles, and coffee. Then I drove 5 kids 90 minutes to Naomi's nephrologist. He said the rise in Naomi's creatinine was too big to be due to discrepancies in laboratory equipment alone--in other words her kidney function has definitely declined, at least some, since last December when it was last checked. He felt it was probably the beginning of a more steep decline in function now. He explained it like this:

Every person has a certain number of glomeruli--tiny tufts of capillaries which carry blood within the kidneys, and which filter or remove toxins from the blood. Most people could lose half of these glomeruli, (one of their kidneys) and never notice the difference because we are born with way more than we will ever need. Naomi was born with kidneys that were filled with thousands or millions of microscopic cysts which have rendered many of her glomeruli useless. When she was four years old we were told she still had about 60% of her kidney function, meaning about 60% of her glomeruli were still functioning, which was plenty to carry her through the last few years. But ARPKD is a progressive disease. The cysts continue to form and they continue to knock out the glomeruli with them, which causes a progressive decline in kidney function. Children with ARPKD progress to end stage renal failure at vastly different rates--some need dialysis within days of birth, while others have made it into their 20s and even 30s before needing dialysis or transplant.

All this I knew before, but what came clearer to me today in his explanation was this: there is a sort of tipping point for many kids where they hold steady for many years with their 60% or so of kidney function, where the kidneys are chugging away at a normal rate and able to handle the demands on them normally, but when enough glomeruli have been destroyed that the remaining 40% or so have to work harder than normal to keep up with demands it can actually cause the demise of the remaining glomeruli to occur faster. It's like a man trying to work double-overtime for months on end--sure he can do it for awhile, but eventually he's going to burn out.

It appears that Naomi's kidneys have hit this tipping point, where the demand is greater than they are able to comfortably meet. This starts the cascade: the kidneys work harder to meet the demand and more and more glomeruli begin to burn out, which only further stresses the kidneys, which only causes their demise faster. How fast she progresses to end stage renal failure, and needs dialysis or a transplant is still a guessing game. Just as one man can work double-overtime for years on end, while another burns out in a matter of months, so it goes with kidneys. I think Naomi's nephrologist would guess that we have a few years--maybe two, maybe six--we really don't know, but I don't think anyone is expecting decades anymore. The hope of Naomi reaching her 20's or 30's without transplant is pretty much out of the question now.

Right now he wants an ultrasound of Naomi's kidneys, since it's been over two years since her last one, just to make sure we don't see anything terribly abnormal (well, besides what we already know is terribly abnormal about them). Then we will repeat blood work in two months. We will not only be watching Naomi more frequently now, but also more thoroughly. Her kidneys are now at the point where their poor function can cause other problems to arise, such as anemia, parathyroid dysfunction, and electrolyte imbalances. I will probably be taking Naomi to the nephrologist every three months or so for the near future.

For the first time today we discussed what will happen when Naomi gets closer to transplant. Our current nephrologist does not work at a hospital that can handle pediatric transplants. He is comfortable following Naomi until either her creatinine reaches 4.0, or her symptoms become complicated by anemia, fatigue, or other renal failure issues. At that point we will have to transfer all of Naomi's care to the children's hospital that is 3 1/2 hours from our house, and we will have to get used to living on the road. This is the hospital where Naomi's GI doctor is, and it may benefit her to have all of her care coordinated at the same place even sooner, but that is something that is really up to me to decide.

Yet another decision we will have to make as this all unfolds is whether Naomi would benefit from a combined kidney/liver transplant or whether to transplant just the kidney and hope that her liver holds out without major complications. We know she currently has portal hypertension. We know this is causing her white blood cell counts to drop, and puts her at risk of episodes of internal bleeding or life-threatening infections. The question will be, as we get closer to kidney transplant time: is her liver going to be in need of transplant as well in a short amount of time and would it be better to just do them both at once? I know of at least one boy who had only a kidney transplanted, and has spent the last nine months since transplant battling one liver-related complication after another and is now looking at liver transplant less than a year after kidney. These are very difficult decisions to make, but the two best experts on ARPKD/CHF have recently released a paper recommending that children with significant liver involvement should receive combined transplants. The question will be, is Naomi's significant enough to warrant that?

There will be other questions to face as well: should we use a living donor or deceased donor? Who should be tested for donor compatibility? Should we get used to commuting or look for temporary housing nearer to the children's hospital? And the list goes on... But those questions are for another day. We could possibly still have five or six years (maybe more?) before we need to face them.

Today Naomi feels great. She's playing "fairies" in our backyard with some neighbor kids as I type. She's excited to be in swimming lessons. She's looking forward to going back to LoveWay for horse riding next week. She's a normal kid, in so many ways, and I have to remember to be thankful for the last nine years of "health" that she has had. They have been a blessing.

I'm not sure how to feel about all of this quite yet. It is sad to let go of the hope that Naomi would reach adulthood before this all happened. It seems very overwhelming to think about, yet could be so many years away that I can't get all bent out of shape over it just yet. The next round of blood work in August will tell us more about how steeply the decline is happening. If the creatinine stays the same, we may be able to breathe easier on another plateau for awhile. If it is steadily rising, we will have to buckle up and hold on. Time will tell.