Dilaysis blow outs: what, how, why and what to do

Belinda emailed me last week asking about her blown fistula. It thought the response could be valuable information to anyone who has just started the BigD.

Belinda:

I just started Dialysis one week ago, this being my second week. Today something went wrong and blood was everywhere and my arm was so swollen they had to cut me out of my sweater. The nurse tech said maybe I had a clot my arm is black and blue and hurts, hopefully it will heal before I go back Monday. My question is how do you know if it’s your arm or if it was the fault of the tech? And what do you do, because I don’t want to make someone angry at a place i have to go to three times a week.

Here’s my response:

Hi Belinda, I’m very sorry to hear about your arm. I and pretty well every other BigD member know exactly how you feel. At least you are not alone. What’s happened is called “blowing” your fistula. It happens when the needle (which is very sharp) pushes right through the fistula wall so that the blood from the machine pumps directly into the flesh and muscle around your fistula. Blow outs are painful, they are dramatically ugly and the extensive bruising lasts a few weeks until your body dissipates the blood (and mental anguish and irritation).

Unfortunately, blow outs can be common in the early days in the life of a fistula, because the fistula walls are very soft and new. Even a small arm movement or inserting the needle a little too vigorously during cannulation will do it.

As for who is at fault, no one does it deliberately. If it happened before you went on the machine, it may have occurred during cannulation, though as I said, it is especially tough to get the needles right during the first few weeks of dialysis. If it happened during the run, it may be that you moved your arm just a bit too much, and inadvertently pushed the needle through the fistula wall. As you say, you will be there three time a week for quite a while, so put it down to experience (unless it happens regularly, then it’s time for another unit).

The good news is that as your fistula gets older, the walls get tougher, you get more savvy, and it is less likely to happen. Have a look at my posts on getting the needles in, so that you know what’s happening inside the fistula and how to avoid blows in the future.

Also, from what you say, it was a few minutes before anyone noticed that it had blown. From your part, that is simple lack of experience (who knows what is normal during the first few weeks?). Unfortunately, if the dialysis staff are not nearby at the time, the blowout can be quite severe before they take action (which is why you need to be able to recognise one early and let them know ASAP).

How to recognise that your fistula has blown and what to do

Either needle can have a blow out, but the effect is dramatically different depending on which one blows.

If the arterial needle (the one closest to your wrist, supplying the blood to the machine) blows, the machine will alarm quite quickly: this is because the needle is no longer in the fistula, the blood supply slows dramatically, the machine sucks harder and this extra negative pressure sets off sensors in the machine. Some blood will seep from the fistula hole into your arm, but not much. Applying pressure to the blow area for about 5 minutes limits the damage, which will be barely noticeable a day or two later. This is the least common blow out.

If the venous needle (the one further up your arm, delivering the cleaned blood from the machine back into you) blows, things can be a little more dramatic. The machine takes a few minutes to alarm because it is happily pumping blood into all that empty space next to the fistula. It takes a while to “fill up” that area until the back pressure sets off sensors that stop the machine pumping. The resulting overflow of blood into your arm can be painful, distressing and the resulting bruise takes weeks to gradually disappear.

What can you do to minimise the blow out?

Firstly, be aware of how your arm feels during normal dialysis. If something changes in how it feels, it may have blown: a short stabbing pain (where the needle has gone through the fistula wall) is a good indicator. Unfortunately, you often can’t feel the blood going into your arm until there is a lot there.

Secondly, keep an eye on how your arm looks during dialysis: if it starts to swell, it has probably blown.

If you think it has blown, act quickly: clamp off the venous supply line, either with the in-line clamp or an arterial clamp; failing that, just clamp or knot the line with your free hand like you would a garden hose. The machine will sense the increased pressure and stop pumping. Then call out for help, press the nurse call button, etc.

Your nurse will remove the needle and re-cannulate in a different location, to resume the dialysis, or to return the blood in the lines to you and end your run early, depending on how long you have been dialysing.

I’m sorry to say that there’s not much you can do to reduce the impact of a blow out. You will get an almighty bruise which will be sore for a while. Many people recommend Hirudoid or a similar bruise reduction cream, but I haven’t found it to be particularly effective. As I said, the chance of blow outs reduce as you become more experienced, but they still happen (I had one about 3 months ago).

The only plus is they look amazing: flash your arm or photos of it to impress relatives, induce shock and awe in strangers or scare small children. Better still, keep vigilant and keep your good looks.