Monday, February 25, 2008

Ascites, kidney function and prograf

So last I left off, we had (hopefully) discovered why Ananya was leaking so much fluid from her belly (ascites) - the biopsy done Friday revealed rejection. Steroids were started in the hope of tamping the rejection down, and we were in a wait and see pattern.

Over the weekend Ananya's ascites did definitely get better, though she continues to still have a large amount of ascites. I really really hope that this means that this rejection she's having is steroid responsive. Ideally the ascites would be completely gone, but I would be a lot more worried if the amount of ascites she was having hadn't changed. My other worry (as I had noted in the last post) was supporting her without complications through this episode of massive ascites. The huge leakage of fluid from the vascular system into the belly that occurs makes fluid management difficult. Ananya is not able to drink enough fluid to keep up with the large losses of fluid into the belly. Since the fluid isn't in the blood, the kidneys don't see as much volume and begin to complain - they 'complain' by appropriately not making much urine. The kidney thinks you're in the desert b/c its not seeing any fluid and goes into massive fluid preservation mode. Of course, the truth is the body has a huge amount of fluid - its just in the belly and not in the vascular system. This is called total body volume overload but reduced effective arterial blood volume. Eventually the kidney will start to show some wear and damage. The usual marker used for kidney function is Creatinine. Ishani's creatinine which had been hanging at .2 - .3 went to .4. Her Blood urea nitrogen (BUN) also sky rocketed from a low of 4 to 21!. The ratio of BUN to creatinine is a poor man's measure of dehydration. A high ratio indicates dehydration. Now things are not as easy as this b/c there are multiple other confounders. She is on an antibiotic called Bactrim that has been shown to raise creatinine and the steroids she started in massive doses by itself raises the BUN. So what's going on?

In the face of this myriad of data - one thing was clear - Ishani was simply not making wet diapers. She would have the barest smidgeon of wetness - when she used to have 6-8 v. wet diapers in the past. That was enough to make my plea to the team that she was still dry and may need some extra volume. Sure enough, after receiving extra volume in the afternoon on sunday, Ananya had a nice wet diaper. and continued to have a couple more wet diapers. Now why should I be so concerned? Well Prograf - which is the immune suppressive medicine Ananya will be on for the rest of her life has as a complication renal dysfunction. With older generations of drugs as many as 70% of kids would manifest some renal dysfunction over the long term. The amount of renal dysfunction is related to where your kidney function starts with and the total dose of immune medicine (prograf) you recieve. So I want to make sure the team is on top of making sure she doesn't come out of this massive ascites episode with some renal dysfunction thats significant in the long run. Being an adult MD I'm still not clear about what the significance of a Cr. rise from .2 to .4 is, but I am concerned if she's making small amounts of urine- b/c it suggest a kidney under stress. After all this fluid, etc. what happened to her kidney function - Her Cr. stayed at .4 and her BUN that had made a steady march up came down from 21 to 17. More importantly her wet diapers continue. So I'll continue to research the relevance of the Cr of .4 in a 1 year old, but am a little mollified about the urine output and a BUN going in the right direction.

I'm still hoping this ascites vanishes down to nothing soon....

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