Dialysis, Boiling Frogs and Fistulagrams

FrogWith all things BigD, I don’t like surprises.  Yet they still arrive, even when I think things are going well.  It can be a lot like the story of the boiled frog.

Put a frog into a pot of boiling water, it will leap out straight away to escape the danger.  But, if you put a frog in a pot that is filled with water that is cool and pleasant, and then you gradually heat the kettle until it starts boiling, the frog will not become aware of the threat until it is too late.

The lesson is to always be watching for slowly changing trends, not just the sudden changes.

I have known about the boiled frog lesson for years, but it still catches me out.

My most recent frog event began with barely noticeable weight loss.  Three months ago, my dry weight was 71.5kg (158lb).  I felt fine after each BigD session, with my after-dialysis blood pressure was around 125/70.  Life was sweet.

But slowly the after-BigD BP crept up, not over days but weeks.  In response, I gradually lowered my base weight, first by 0.5kg (1lb), then 1kg, then 1.5kg (3lb) and each time my BP would gradually rise again.  All this time I seemed to be fine.  Then I realised that I had started to have a little “rest” at home after each session because I felt a bit tired (not something I normally do).

I am still using 15 gauge needles (soon to move to 14), my pump speed is always around 370 mL/min, which gives me a good Kt/V dialysis efficiency.  So what could be wrong?

It was then that the image of a rather sweaty frog in lightly bubbling water jumped into my head.

When in doubt, ask the expert.  I discussed the BP/slow weight loss with Chris, my unit manager and she reminded me that gradual weight loss is a symptom of inefficient dialysis.  And that the most common reason for inefficient dialysis is a blockage (eg a clot) or narrowing in the fistula.

If the fistula has some kind of obstruction, or where the fistula walls have narrowed to the point where blood flow is affected, then instead of getting fast, smooth flow (like with a broad open river), you get fast, turbulent flow (like river rapids).  The blood recirculates and effective flow is reduced, so less gets filtered during the BigD run.

The effect on dialysis efficiency can be small – be hardly noticeable in the short term.  But quite obvious as time goes by.

So last Wednesday, off I went to the vascular surgeon (the guy who creates the fistulas) for a review.  He too suspected a narrowing or blockage (while the blood was flowing OK, he thought the thrill – the buzzing – was a little subdued) and scheduled a fistulagram for the following Friday (yesterday).  Normally a fistulagram is just a look, usually by a technician, to confirm that there is a problem.  Then the vascular surgeon schedules a time to fix the problem.  But this surgeon does his own fistulagrams and treats it (called an angioplasty) on the spot.  Very convenient!

So, how is it done?

The procedure was scheduled for noon, so I had to fast after 8am (no great hardship!).  After the usual checks, form signings and wrist and ankle labels, I eventually found myself on the table in an operating theatre set up for inserting catheters into a variety of veins and arteries.  There, quick smart I had a drip put in, a short squirt of Valium or the like, and things went pleasantly fuzzy.

The surgeon inserted a catheter onto the base of my fistula (closest to the wrist) and through the catheter a flexible probe that he used to explore the fistula from the inside.  My arm and the probe’s progress were displayed on a screen next courtesy of an x-ray machine.  I watched it worm its way along until it was at my bicep, where it found the first narrowing.  Out came the built-in balloon which was slowly expanded, to enlarge the fistula.  It was an odd sensation seeing and feeling this going on, and just a little painful.

He then continued his journey until the probe reached my shoulder.  Once again a small blockage was identified and dealt with.  This time quite painlessly.

Then it was all over, and I must have dozed off.  I woke in a small recovery ward and the surgeon dropped by a few minutes later.  He said all went well, checked my fistula and declared the thrill was loud and clear (I’d like to say I was thrilled, but I just smiled).

Within an hour I was in a discharge area.  Julie arrived to collect me (a very welcome sight).  I had a sandwich and a cup of tea, got dressed and we drove home.

From arrival to departure it took about 3 hours, and a fine time was had by all.

This was good, because I dialysed the following morning (today) at 0650.  Without incident.  I also had a little rest when I got home, but I put that down to yesterday’s drama.

I expect my dialysis will be genuinely efficient for the foreseeable future.

Though the surgeon did say that it is possible the ballooned area may shrink back over a couple of months and I will need a checkup then.

That’s fine with me.  I’ll think of it as a frog temperature monitor.

4 thoughts on “Dialysis, Boiling Frogs and Fistulagrams

  1. Our Fresenius clinic checks the flow rates on our fistulas every month. A low number has had me back at the vascular surgeon to do angioplasty three times. This is a common maintenance procedure on fistulas. Does your clinic not do this flow test and report the results to you?


    • Hi Derek. Yes, they do some kind of flow test, but that test can’t pick up blockages outside the fistula area, further up the arm and the shoulder (called an occult stenosis). This is because the blood flow is fast but inefficient through the fistula and then flows away through a network of ancillary veins at the upper arm and shoulder. One of the best tests is to hold your arm above your head an see how fast the fistula drains. (This was my third fistulagram and second angioplasty). Regards, Greg


  2. Great news about the frog. It’s just what I’m going through except no weight loss. I have been on the D 1 yr 1 month and on the transplant list for 1 year. Blood pr creeping up and gained 4 lbs. Had my fistula cleared 2 month ago and I really feel great I am 66 and hoping and praying for a kidney.


  3. Pingback: Dramas on the Dialysis Days of Our Lives | Big D and Me

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