Heparin dosing for nocturnal txs

Dear Dr. Agar,

How is the heparin dose for nocturnal txs determined?


We use, broadly, about 1000u hr of conventional sodium heparin via a heparin pump. I am aware that some have used a once only dose of low molecular weight heparin but we have not gone this track as i am concerned that the effects will not reliably last the full duration of the treatment and we have had no issues with the use of standard heparin.

As with all other answers I give, this is individualised up (mainly) or down (rarely) according to individual need. If there are clotting issues of worries, we might dial it up to 1250 u/hr, but this has not been a common need.

Again, the correct dose for any on individual can only be determined by that individual patients’ treating team, according to that paients’ dialysis experience and the perceived need.

John Agar

Dear Dr. Agar,

Do you usually start with a heparin bolus?

Dear Kathleen

Yes, we still use standard, unfractionated, sodium heparin with a regime similar to that used for our conventional patients: a bolus 1000 + ~1000/hr. We have had no issues with this. We do routine BMD at 12/12 intervals and have found no evidence for long term osteoporosis … f/u now 10 years … though admittedly, we have not perfomred bone biopsies. However, BMD seems better preserved than in our dialysis population as a whole. We have presented this data at several ANZSN’s over the years.

Dear Dr. Agar,

Is the 1000 bolus given with the syringe via the heparin pump or straight into the access? Also, you seem to say that you run heparin until the end of tx. Here, a number of patients have said their heparin is set to run an hour prior to the end of tx.

I recently asked to have my heparin dose reassessed, because it seemed high to me. I asked my nurse for an explanation of how heparin dosing is figured. Since I started nocturnal, I have gotten a bolus straight to the access of 4,000 units, which is what I used on short txs, and was instructed to use 9,000 units in the syringe. I also was instructed to give 2000 units into the dialyzer to keep the fibers open, but for that, after prime we do hang a new saline bag.

I have never had any bleeding post tx so this has worked for me, but I had just wondered if it could be tailored down somewhat. I also went from 8 hr txs to 7 hrs txs months back without a reassessment, so that has meant that excess heparin has remained in the syringe at take off.

After doing the new assessment, my nurses determined that I should only need the same bolus of 4000 plus another 4000 or so in the heparin pump syringe. They now have elected to stop the pump 1 hr prior to the end of tx.

My nurse told me I could stop adding the 2000 units into the dialyzer as they had tested this in-center with FR machines. There, they gave 1000 units, but she said they found it did not make a difference. I use NxStage, and since I stopped giving the 2000 units, a few txs ago, have observed clotting in the dialyzer. Last night, I resumed giving the 2000 and clotting ceased. So, on NxStage, using a little heparin in the dialyzer running at a 200 BFR is necessary for me.

Interestingly, one night this week, although I got the 4000 bolus, my caregiver forgot to turn on the heparin pump and I slept well through the entire tx with no alarms. I did observe some clotting in the morning in the dialyzer caps and more blocked fibers than usual, but was able to rinse back with no problems.

I told my nurse how differently heparin is given in your program. Nocturnal is totally new to our team so they are learning best practice as we go along.

Interesting, that as you’ve said before, you don’t see problems with BMD despite using so much more heparin with nocturnal txs. I was tested previous to nocturnal after years of in-center and the outcome was not good. Maybe I should be tested again to see if there has been improvement.

Dear Jane

In fact, much of the heparin dosing is based on empirical practice and ‘what has been done and works’. We us heparin doses literally ‘transplanted’ - should I use that word? - from our conventional dialysis practices. One has to start somewhere - and that’s what we did … to simply to follow our standard dialysis practices and apply them to the nocturnal process.

We find 1000 or so units at the start and 1000-ish an hour is practical, it suits most situations and is a sensible starting point from which to begin.

Again, though, I must emphasize that what I answer here is a generic answer - every patient is different, every situation has its own peculiarities, so what might suit one patient may be varied in another or varied in the same patient according to changing circumstance. Is 1000 bolus and 1000/hr right for all? No! it isn’t. But its a reference point that we use to kick off … and it so happens that that suits most patients in our nocturnal program, most of the time.

I don’t actually recall saying anything about whether or not we d/c the heparin before the end of the treatment … but, in fact, broadly, we don’t … it’s a bit difficult to do so when different patients wake at different times and after different ‘hours’ of treatment … and some nights they might sleep soundly through the night but on other nights may wake early … but our patients do turn off their heparin pump when they wake at the end of a planned duration of treatment and/or if they are approaching the end of their goal re treatment time.

But … we aren’t rule driven. We try not to lay down laws. We try to treat our patients as sensible contributors to their regime rather than to drive the treatment process by ‘requirement’.

Clearly some patients will need a little more heparin, some maybe even need less. That is judged by individual observation in individual patients and is most often worked out in the shorter day-time hours of the training program with our nurse trainers and then simply applied, by extension, to the overnight program.

Do we have bleeding issues? No, we actually don’t. Or clotting problems? … also no. The only bleeding issues we see relate to access malfunction (for example - though not restricted to - stenosis with an elevated venous pressure or to a mis-cannulated button). Anti-coagulation has not been, in our experience, a cause of bleeding. The only clotting problems might be an observed fibre-darkening in some fibres in some patients during training … solution? … a tad more heparin.

It may all sound a bit trial and error … and, indeed, that’s just what the training process permits it to be until the dosing practice matches the specific patient. My first answer said (I think) 1000-1250(ish) units/hr. That’s about what we give. Most patients. Most of the time.

I can’t say more.

Dear Jane

My apologies … due to an error of mine, my answer to your post appears 3 or 4 posts back in this thread. I boo booed. My lack of ‘techie’ skill, I am afraid.

Read back a couple …

Dear Dr. Agar,
Actually your latest post came in just fine right under mine, so your ‘techie’ skill is right on!

Thanks for the expanded answer. I just need to understand is the initial 1000 bolus in your program given directly into the access, or via the heparin pump?

Jane: I am a bit non-plused by this question … I am at a bit of a loss to understand why/how one might, could or would want to give a ‘bolus’ dose via a heparin pump which is ‘heparin-loaded’ for an overnight, ‘duration’ infusion.

A bolus is just that … a slug! a hit! … and I would have thought that, by definition, a bolus would be routinely given directly into the needle.

As for what might be the correct dose for any one individual, whether as the bolus or as the per-hour infusion dose … these will vary, patient to patient and, even in one patient, may vary from clinical circumstance to clinical circumstance and are always best determined and adjusted (if adjustment is needed) by the treating unit.

It would be unwise for me to comment further on this aspect and, if you have issues with heparin as it pertains to you, as an individual, I would suggest you discuss these with your team.

I can only say what our average doses and practices are in my own service.

Lol, now I have had a lack of techie skill. I’m totally new to heparin pumps and did not get a manual with it. I simply wondered if a pump could be programmed to give a bolus. Well, I guess not. And as far as the ask your doctor advisory, I always do which is why I have been able to keep on truckin. Yes, they are the experts which is why I always bring new info to them for their approval. At present, they are babies when it comes to nocturnal, but I have a good team who is always open to best practice ideas.