The danger of setting too high a goal on nocturnal

I have wondered what can happen if one sets too high a goal on a nocturnal tx. I just read a post about a patient who experienced this. The same thing happens that happens on a short, in-center tx- the patient painfully cramped and was about to crash while he clammered to recall emergency procedures. He should win an award for maintaining his composure under extremely trying conditions. He was able to call for his wife to assist him. When they tried to call unit could not get in touch with anyone at first. Would be interested to know how those who do home hemo alone would of handled same.

One: If my pre-tx BP is under 120, I proceed very carefully, checking my BP a number of times during the first half hour, double checking my goal calculations, maybe drinking more before the treatment starts and not counting it in the UF goal, etc. Normally, I only have to do a round at the begining of treatment, but if I see that my BP on treatment approaches 110, I may decide to give myself a bit of saline and then check my BP several times. In other words, if it looks like there’s any chance my BP will go under 110, I take the initial steps I was taught, and, if after giving myself two 200ml saline infusions my BP is still too low, I don’t dialyze that night. Simple as that. You just don’t take chances with hypotension. If BP is Ok the first half hour, it’s going to stay Ok, because we’re not talking very high UF rates here due to the length of the treatment.

Two: UF goal, like dry weight, is not something that’s written in stone. I never dialyze with my UF rate much over 400, and preferably, I keep it under 400 if I can. If it is over 400, I can simply lessen the goal and/or add an extra hour to my treatment. I normally do 7 hours, but I can do 8 hours anytime I want to (I’m limited to 8 hours without running out of dialysate concentrates). To have a UF goal that is too high, you would have to weigh considerably more than your dry weight.

Here’s an example. Say you are 3 kg over your nominal dry weight. That’s 3000ml. Add the 500ml for rinseback, and that gives you 3500ml. For a 7 hour treatment, that would give a UF rate of 500. Too high. You don’t want the UF rate to be much over 400. So you try 8 hours. That gives a UF rate of about 440. This is Ok. If you want to stick with 7 hours, you just lower your goal a bit. It makes no difference, because you’re dialyzing every night.

To be 3kg over nominal dry weight, you have to have drunk 3000ml, plus any amount you urinate, plus any amount you sweat, plus the amount your lose just breathing. That’s a lot of fluid. But the important thing is that as I said, dry weight is not written in stone. You can play around with it a little if you have to.

Because I take these precautions, I don’t wear the BP cuff overnight. However, I could if I wanted to. I would simply have to turn on BP measurement and set an appropriate interval. It would alarm if the BP went lower than the set limit. But you don’t really want a BP cuff going off all night. It would make it hard to sleep. So, nocturnal hemo people usually don’t wear the BP cuff. This is why in my program, we’re not supposed to allow systolic to go under 110.

When doing daily hemo, you can gradually get lower and lower BP as you gain real weight. Trust me, because of the free diet, a person can easily gain 10 lbs or more in just a few weeks. If you don’t talk to your nurse about adjusting dry weight upwards gradually as you notice your BP is getting lower, you will eventually run into low BP problems. But you will probably start getting some signs first, like feeling dry (dry mouth/throat, headaches, nausea, maybe some slight cramping at the end of tx. As a home hemo patient, you are your own nurse, so, you have to pay attention to what’s going on - and you had better do so. You can’t be cavalier about it. When you pay attention to how things are evolving over time, it’s improbable that a stable patient will suddenly experience hypotension on treatment. If you can’t do that or you aren’t willing to, you’re better off staying in centre (just using a rhetorical “you”, not meaning YOU).

Pierre
P.S. 99.9% of the time, I’m nowhere near 3 kilos overweight by tx time. Usually, I have plenty of room to drink something, even though I don’t watch my fluid intake during the day. This means that I get an extra 300-500 ml to play with. In other words, I can lower my UF rate simply by not drinking the extra before or during tx.

Well I read that message too, and BOTH he and his partner “forgot” that when you feel faint and start cramping badly that you need to infuse saline. This is the MOST basic thing we are all taught. What amazed me most is that having a partner really didn’t help as she too didn’t do the “right” thing. He also immediately stood up which is a big no no, you should sit first and make sure you are okay…

Can’t say the story really scared me, but sounds to me as if he may need to reevaluate his dry weight, he wasn’t really removing that much to have had such a bad reaction.

Cathy

Where did you guys see that story?

With nocturnal, you’re expected to be sleeping, plus, you’re already lying down. Nephs with nocturnal experience tend to err on the high side for dry weight precisely to prevent hypotension. If you’re sleeping, you might not notice any of the classic signs of potential hypotension, so, as I explained, this is why it’s necessary to be very aware about blood pressure pre-treatment.

It’s also important to keep in mind that only stable patients should be on nocturnal hemo.

Pierre

I basically agree with whay Pierre has said, but might add a couple of points. First, if BP is a little low before starting dialysis our first step is to eat a half-dozen olives (if you don’t like olives dill pickles or anything equally salty will do). This heads off the need for saline much of the time. The first BP immediately after going on is usually the low point. I would not give saline then unless the BP was below 110 as the second measurement which we do 15 minutes later is usually higher. I migfht also use sodium modeling as an interim step and would always use it if I’m going to give saline. If the second BP is above 115 and Jane feels OK (how you feel is almost more important than the number in determining what you do) then off with the BP cuff and on to sleep. In real crashes we were taught to go up to 700 ml saline, but we’ve approached that maybe six times in about a thousand nocturnal treatments.

The other point is that rinseback (at least for the 2008K Fresenius machine with F160 dialyser plus Medisystems tubing set) is only about 250 ml – we use 300 to also account for the on/off flushes. A mistake I’ve found many hospital acute dialysis nurses make is to assume that you have to double this number to account for going on and then coming off. If you think about it carefully you’ll see this gives you far too much saline.

Mel

Pierre, he posts on another list. He usually does nocturnal but decided to to a day run so wasn’t asleep. To be completely honest the post didn’t make complete sense as he said something about making a mistake computing how much to take off because he was doing a day run vs. a night run, but using the Fresenius it makes the calculation. I didn’t question him as it didn’t seem useful.

Cathy

Hi Cathy

Well, that might explain it. A shorter day run vs a long nocturnal run would obviously guarantee a much higher UF rate for the same goal. So, there would certainly be a greater chance of hypotension. As you said, it’s only a matter of being aware of the signs. As Mel said, if the BP is good enough at the beginning of a nocturnal run, it’s not going to go down enough to cause hypotension.

By the way Mel, I eat a few olives too if I have to, and sometimes I’ll have a glass of V8 with added salt :slight_smile:

For nocturnal runs, they don’t like the UF rate to be much more than 400, although I’ve done 500 without any problem. For day runs, the same UF rate limit for at home dialysis is 1100ml/hr.

All the above and previous posts just to reply to Jane that nocturnal hemo is not dangerous in that way. The UF rates you go with just aren’t high enough, plus there’s also the advantage of low dialysate and blood flow. All of this combines to make it a very gentle while extremely effective dialysis.

As an example, I just got my last blood work results. Nothing in my post-tx bloodwork would cause a doctor who didn’t know to guess I even have kidney failure at all.

Pierre

I read teh same post, though he wasn’t doing his nocturnal dialysis he was doing a day dailysis. Also, he may just have not calculated his the difference between is predialysis weight and his dry weight. ( it has been known to happen :slight_smile: ). The machine only calculates what you put in it.
And having a helper while doing it home does help alot, that helper has to know how to administer a saline flush.

I actually have a laminated copy of the procedure attached to my husbands machines at all times. I think what happened to that guy is he just learnt a lesson in the fact that you should keep up with your emergency procedures. thats all.

I think his first sign of trouble was the cramping, that is when he should have administered his first flush of saline, expecially if he didn’t usually experience this during dialysis. The first sign of something wrong, however We all make mistakes, we all panic. He worked it out.

regards Queenie.

I read teh same post, though he wasn’t doing his nocturnal dialysis he was doing a day dailysis. Also, he may just have not calculated his the difference between is predialysis weight and his dry weight. ( it has been known to happen :slight_smile: ). The machine only calculates what you put in it.
And having a helper while doing it home does help alot, that helper has to know how to administer a saline flush.

I actually have a laminated copy of the procedure attached to my husbands machines at all times. I think what happened to that guy is he just learnt a lesson in the fact that you should keep up with your emergency procedures. thats all.

I think his first sign of trouble was the cramping, that is when he should have administered his first flush of saline, expecially if he didn’t usually experience this during dialysis. The first sign of something wrong, however We all make mistakes, we all panic. He worked it out.

regards Queenie.