Dialysis and Blood Pressure (and AF)

Without fail, we all have our blood pressure measured before, during (usually hourly) and immediately after dialysis.

Before dialysis

There are several reasons for this.  It’s taken before starting to see what effect the fluid we are carrying is having on our blood pressure.  High blood pressure is usually caused by too much fluid, so it is a good indicator for staff that we need to lose some.

I put on between one and two litres between sessions.  That’s a fairly small amount, but then I dialyse five days per week, primarily so that I don’t put on too much fluid.  As a consequence, my starting blood pressure rarely rises above 150/75 and my pulse is usually around 55bpm.

The difficulty of putting on more than this between runs is what it does to the heart.  The body can’t dispose of the fluids and toxins, so they go into the bloodstream.  In order to cope, the heart swells up and pumps harder, so blood pressure climbs.  When there is just too much fluid, it seeps through the cells of the body to pool in the spongy bits – the lungs, making it hard to breathe, into various cavities and into expandable bits some distance from the heart, like ankles, arms, fingers, etc.).

Initially, the heart can handle this swelling and extra work.  But if it becomes a constant problem, we get complications.  Like Atrial Fibrillation (AF) and heart attack.  In fact, the biggest cause of death among BigD members is not directly related failed kidneys at all; it’s heart failure.

So the before-dialysis blood pressure is a strong indicator of fluid level, and every dialysis nurse and technician keeps a close eye on it (the reverse also applies: low BP and you get a smiley face).

During dialysis

The main reason staff take blood pressures during BigD is to make sure that it does not fall too low, which can happen if too much fluid is taken off too quickly.  Very low BP can cause a loss of oxygen to the brain, then a loss of consciousness.  Called “going flat”, first you feel tired, then faint, then you slip into unconsciousness.  It can all happen within a few minutes.

In most cases people recover quickly.  Staff press a special setting on the chair which lays the patient flat, then raises their legs above their head to get some blood to the brain.  Then they place an oxygen mask over the face, stop the machine taking off fluid and usually give the patient a few hundred mls of saline to build up the fluid volume.

There are some indicators for staff when someone goes or is going flat.  Some people make a loud snoring sound.  Others freeze in a fixed position, sometimes with their eyes open.  If a staff member thinks a person is going flat they usually call their name loudly a few times, tap their foot or arm, etc.  If they respond, things are fine.  If not they have to act fast.

How often does this happen?  In my experience, someone goes flat (or nearly flat) about once every few months.  All are dealt with quickly and they are fine within a few minutes, with no lasting effects.

However going flat is serious and if left unattended can be fatal.

A couple of years ago in a hospital BigD unit one of the older patients used to sleep with a blanket over his head to cut down distractions.  Unfortunately, one day he went flat in this position, and because no one realised it, he passed away.  Since then facial coverings have been banned in units around Australia.

So don’t be upset next time someone wakes you up or taps your foot to take your blood pressure.

After dialysis

Typically after BigD, staff measure blood pressure, firstly to make sure we are ok to get out of the chair and remain upright, and so are OK to go home.  Secondly it is a check: if the BP is within an acceptable range, then it is likely that the correct amount of fluid has been removed and we will probably now be at our required dry weight.  They confirm this when we weigh before departure.

BP can be elevated for many reasons other than being overweight: I find that if I am watching an exciting movie, having an animated conversation or are concerned or tense (eg potentially late for an appointment) my BP is high.  After a few minutes it usually reverts to normal.

BP and AF

I mentioned AF before.  AF is where the heart beats both fast and out of rhythm.  It can cause palpitations or a fluttering or irregular heartbeat, chest pains, dizziness or fainting spells.  Untreated, complications may include stroke (because the inefficient heartbeat allows blood to pool and develop clots, which can flow to the brain) and permanent heart damage or heart failure (if the heart rate ends up being very very rapid for a long period).  Treatment options include medication, surgery and electric shock therapy.

AF is very common in us BigD patients because of the regular fluid overload on the heart.  I’ve had it several times.  It can sneak up on you.  Because it comes so irregularly, it often takes me a couple of weeks to recognise it.  Usually I think I have a bug, because I’m easily tired, run out of puff, find it hard to get out of bed, etc.

But the AF light goes on when I go on dialysis because every time I have AF my BP drops and my pulse rises.  For me, the raised pulse is the big clue, because my irregular heartbeat is so inefficient that it has to beat faster just to keep the blood moving.

So for BigD patients there is a hidden side effect of AF: the drop in our BP increases our risk of going flat.

The message here is to be aware: if you feel unwell and your before-dialysis BP falls, check your pulse for AF.  If it’s erratic, tell the nurse or technician that you may be at risk of going flat and ask for regular checks through the run.

It’s a little extra hassle, but so what?  if you’re like me, you have enough drama in your life already.

8 thoughts on “Dialysis and Blood Pressure (and AF)

  1. Very informative .
    I am trying to learn as much as I can about kidney failure and dialysis.
    Someone dear to my heart has just begun home dialysis but lives so very far from me.
    Between the great info I am getting from him and your blog I am understanding more and more.

    Thank you



  2. Also,consistent BP above 180 needs to be double checked manually as some dialysis patients can have highly calcified arteries resulting in false high BP. This is when the arteries are so calcified the automatic BP cuff cannot properly compress the artery & therefore detect the corrrect BP. This can manifest itself unexpectedly. It is very important to double check high BPs manually as a false high BP can result in BP over medication and attempts to take off too much fluid.
    Also,a very good way to stop going flat is to keep a sharp eye on your blood volume (if your machine comes equipped with a crit-line) and to try to do as much of your session in a supine (lying down) position as your blood/fluid volume is greater this way (more fluid is available for removal).
    Check out this link for tips on blood volume guided dialysis: http://www.crit-line.com/Trainingmaterials/SELF_STUDY_GUIDE1.pdf
    And if it turns out you do need manual BPs taken for correct/accurate measurements, make them do it!!!


  3. My dad has a blood clot in his neck. Doctors turn him away and refuse to take the blood
    clot out because he doesn’t have insurance. Is this legal? I get that doctors want their money, but seriously? It’s ok to let someone die in
    this country? Please, someone, explain to me
    how this is ok or legal..


  4. A friend of mine is a dialysis patient but due to stress at home barely eats once a day sometime s she goes days without, im soo worried she’s had soo health problems in her late 20 s what the risks if continued please could u gv me some advice , anybody?? thanku


    • Hi Ash. Kidney disease and dialysis can be major stressors by themselves. Adding stress from home may just be too much for some people. While there’s not much you can do about the kidneys, if the dialysis environment is right, it can be a positive and low-stress community, even a retreat. Not knowing anything about her situation, its hard to make suggestions beyond the general: is there a way to minimise the home stress by making some changes? eg identify one thing that can help lower the stress levels and work on that; or get involved in something she is passionate about; consider going to Yoga or Pilates. Anything to get her mind off her troubles.
      Regards, Greg


  5. hi my husband has af on dialysis and low blood pressure has had quite a few bad turns whle on dialysis he only started in jan but has gone flat about 6 times since starting he says he is not feeling any better


    • Hi Anne. It is tough when you have AF on dialysis. I find I go into it if I have too much fluid taken off too quickly. It is a real balancing act for your husband and the staff to find the best combination of fluid removal with low BP and going flat. Sometimes it is just a matter of experimenting to find the right balance. One of the patients in my unit used to go flat a lot, and our unit manager suggested that she have a glass of ice throughout the run. She found that slowly sucking the ice (so she didn’t put on more fluid) seemed to balance out the effect of dialysis. Maybe that’s worth a try. Maybe it will just take time to adjust. Let us know how he fares. Regards, Greg


  6. My wife has been on dialysis about 5 years, we started at home with the 2008h about 2.5 years ago, and in May 2016 on the Nxstage system one. All was good at first, but the last 4 months she has had problems with high HR close to the end of Tx. I’ve been working with the nurse trying to find the reason. They think it might be low potassium. Can you give me any other ideas?


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