Afib and dialysis

My husband has afib in addition to doing home hemo. His bp tends to drop really low during dialysis, like 85/45. Is that normal? He feels fine - no lightheadedness.

Re Atrial Fib and Low BP on home dialysis

No, this is NOT normal but unfortunately, there is very little information in your post to guide a certain answer. However, I will give a general response which may at least put you on the right track to resolve this problem.

The first and most important statement in my answer is to make your husbands’ management team aware of this. Their assessment and management of this cannot be replaced (nor should it be) by any internet advice, however well meaning that advice may be.

I would be seeking their assessment, their management (and not mine) for this issue.

That said, the following discussion will likely be similar to the assessment process they will follow - and the potential answers that they will give.

While you advise me that your husband is on home dialysis, it isnt stated whether that is ‘short daily’ … ie: 5-6/wk x 2-2.5hrs … or ‘long +/- slow nightly’ … ie: 3-3.5 (or more) x 7-9hrs. Knowing this makes all the difference in interpreting the limited data given. While this website has long encouraged longer, slower and more frequent dialysis, I am aware that in the US - something which is quite the opposite to what we do here in Australia - home dialysis means (for the majority) short but frequent daytime treatments.

So … why does this matter and are these two ‘home’ therapies so different?

The answer is yes … there are … very, very different.

Patients may drop their blood pressures on dialysis for a number of reasons.

  1. The rate of fluid removal may be too rapid (ie: the UF rate is set high to try to remove excess weight gain … or a normal weight gain but in too short a dialysis time). In this instance, the intravascular volume - the volume of the circulating blood – can fall sufficiently far and fast to drop the blood pressure.

This is a common outcome in (too) rapid, short hour treatments - what I call ‘bazooka’ dialysis - a treatment profile all too often administered in the US.

Though this is commonly a facility-based problem, it can also be encountered in the home if short rapid daily home dialysis is prescribed … a prescription which, in most respects, does not differ much from short rapid daily dialysis delivered in a centre.

But … you say he is well, and his low BP is symptomless. In this case, we should consider if there are other possibilities … …

  1. Many patients, once transferred to the home, actually begin to feel better. They begin to eat better, feel happier, are less institution-bound, and from a biochemical aspect, may be getting better dialysis! Here is where not knowing his home prescription, his hours, his dialysis frequency … or, for that matter, HIM … make answers like this like water-divining – a bit of guesswork.

But, if he IS accessing better dialysis than he was getting in-centre, if he is feeling better, if he is eating well, then his persistent symptomless hypotension (a low BP) may be due to the fact that he has actually gained body weight. In other words, his dry weight is now set too low and he needs to come up a kilo or two in body weight.

In fact, this is my best guess at the correct answer to the problem but it is ONLY a GUESS and only his treating team can assess his dry weight, and advise whether this is the correct answer.

  1. Many patients are on BP medications when on in-centre dialysis. Indeed most centre-based patients in the US seem to be being treated for hypertension (a high BP). When patients go home and have access to better dialysis – again, I cannot say whether that is the case or not as I do not know his particular details – fluid control is better and blood pressure control improves. If this is not paralleled by a reduction in BP medication (most home patients take far fewer anti-hypertensive drugs than centre-based patients), then the BP can be forced too low.

So, if he is on BP medications and these have not yet been withdrawn or lowered appropriately, then this would be an obvious step.

  1. I do not know the state of his heart, nor the duration of his CKD, or whether he has had other modality treatments – eg whether or not he has had one or more transplant periods – all of which may have an impact on the function of his heart.

It may be important to know if he has had an echocardiogram (we do them routinely) to assess the function of the main pumping chamber of his heart (the left ventricle).

If he has had heart trouble (we already know he is in atrial fibrillation – as you said), his poor BP may be because he has a poorly functioning heart and left ventricle which, despite (perhaps) all else being OK, cannot mount a stroke volume of sufficient ‘oomph’ to sustain a strong and healthy BP.

There are a myriad of other issues that may be contributory to his central problem of a low BP on dialysis. Have you gone through all this with his managing team? They must be your first port of call and should sort this issue out for you. It is rarely if ever a difficult diagnosis to resolve and, usually is not a major problem to treat – unless, of course, the underlying problem is such a damaged ‘ticker’ that it cannot be better optimized to sustain a better BP.

Finally, some patients do tolerate low BPs remarkably well … without seeming distress – though the BP you cite does need thought and explanation.

My best guess is this might be a dry weight problem.

Get your husband assessed and seen by your home management team. This is not a problem to trifle with and proper assessment and treatment – and though this may be through a simple adjustment of his dry weight, it may also require further investigation of his heart function.

Thank you so much for the quick response. His team is aware of his numbers, but I will email your response to them. My husband dialyzes 5 times per week, for about 2-1/2 hours. Thank you!

Your team will sort this out but I think the major options are as I have suggested.

One thing always bemuses me - and that is … why do so many US patients go through the efforts of home training (as laudable and as wise as that is) - and yet then do not avail themselves of the main benefit of dialysis at home … ie: the easy availability of adopting a longer treatment time!

It makes no sense to me at all.

The clinical advantages of home care are embedded in two words … TIME and FREQUENCY.

Availing of one and not the other seems, to me, an odd outcome.

The recent FHN trial was NOT helpful on this issue. It was so flawed, so under-powered and so under-separated in terms of total weekly dialysis hours, that despite all the effort that went into it, it should be … no, must be … ignored when considering the issue of total dialysis time.

Your husband still only gets 12.5 hrs dialysis a week. He still has only 12.5 hrs to remove middle molecules and fluids accumulation.

Sorry, but it’s just not enough dialysis time.

It doesn’t surprise me he is dropping his BP during dialysis!

Thanks, Dr Agar! We are doing what our center suggested. I did forward them your response. Maybe they will rethink the total amount of time. I do appreciate your responses. Clare


I will be interested to hear their response.