No fluid gain between treatments...low blood pressure episodes

Hello. I am new to these forums and have searched past questions and topics, but I am still stumped. My husband has a maturing fistula and a CVC. He started in center dialysis about a month ago. Not long before that he was hospitalized because of what we now think was either low blood sugar or low blood pressure episodes. He was severely dehydrated after being prescribed Lasix to remove excess fluid. It worked too well I guess. It caused hypocalcemia. After several days in the hospital with IV fluids his numbers improved a bit. We then attempted a PD catch placement but it was not playable due to scar tissue. Next, the fistula surgery which went well, but is still maturing. Not long after he started retaining fluid again…this time in his chest as well. At this point the doctor ordered the CVC placed so he could start dialysis. They started slow, but he was up to 4 hrs by the 4th treatment. All this pretty typical I guess. However, after the first treatment he has never regained any fluid and or weight. In fact, he has lost. He has had two serious low blood pressure episodes (third treatment with UF) and then just this last week at the end of a treatment in which they said they were not removing fluid, only filtering the blood. This episode was serious and I’m concerned about how it could be effecting his heart. He has supposedly not had UF as part of his treatments since his third treatment. I have read about the UF rates with standard HD, but if they are not removing fluid, I don’t know if this applies? He still urinates, but is BUN is high and phosphorus can be high if he doesn’t take his binder. We are considering nocturnal…is this the solution, or is there something we are missing? His appetite is fine, we watch the phosphorus, potassium, sodium etc and push the protein. I don’t understand the weight loss between treatments and how this could be effecting his blood pressure. Thank you. I would appreciate any suggestions or thoughts.

Obviously I cannot make specific comments about your husband’s management or condition as I don’t know him - nor do I have anything but the bare outline you have provided - but, I can make some broad observations that may or may not apply to his situation. Importantly though, you need to learn to relate to and discuss with his managing team as they are always best placed (by far) to be able to advise you about him and Internet advice, even if well meant, can never replace that direct team connection.

That said, it would seem likely that through a combination of (1) ill health (where body weight loss almost always occurs) + (2) the use of diuretics, your husband lost a significant amount of both body weight and fluid weight. Then, with the introduction of dialysis - first failed PD, then later IJC-accessed HD - the application of ultrafiltration may well have further ‘dried him down’ when there may well have been little or no excess fluid to actually remove.

Significant UF is often unnecessary - or only required via gentle and measured application - in the early phases (ie: the first weeks or months) of dialysis when a residual urine output remains intact. Indeed - and regrettably - UF can be often applied ‘by rote’ from the get-go but without a careful assessment of the underlying volume status. This is not to say that some patients enter dialysis fluid overloaded and in a state of ‘volume excess’ … many do. But, by the same token, many do not and are ‘euvolaemic’ [a state of normal and balanced fluid balance] when dialysis begins. If UF is then applied in this situation, it threatens residual renal function (RRF) and circulatory stability.

As patients settle into HD and begin to slowly improve and feel better, their appetite returns, any weight loss that may have accompanied the end phase of their CKD5 begins to reverse, and body weight begins to recover. If this is not constantly assessed and adjusted for - often requiring a slow up-adjustment of target weight - the unthinking application of obligatory UF (by protocol) ‘seeks fluid to remove’ when there is actually no excess fluid to remove at all. This can lead to persisting hypotension and/or recurrent ‘flats’ during dialysis.

The process of dialysis comprises two components:
(1) solute (waste) removal down a concentration gradient to remove excess solutes (wastes)
(2) fluid removal via pressure-driven ultrafiltration (UF) to remove excess water.

UF should only be applied (or is needed) if or when water excess is present. But, if there is little (or no) fluid (water) to remove, then minimal (or no) UF should be used.

While dialysis is always needed to remove excess solutes (ie: wastes), UF to remove excess fluid is not always needed as many/most patients still retain their urine output as their fluid 'safety valve even when excess solute removal is required. UF is commonly either not required - or only needed in a careful and measured way - in patients with a preserved urine output. The over-zealous use of ‘obligatory’ UF simply causes horrible and symptomatic dialysis as the circulation is destabilised when there is not need to do so, while it diminished or eradicates residual renal function (RRF) when RRF should be being carefully retained for as long as possible.

As I said, some patients DO enter the dialysis program with significant fluid overload, and these patients need slow … but with an emphasis on ‘slow’ … fluid removal - preferably over many dialysis treatments - to slowly restore their fluid balance and volume status to normal.

But, for those patients who start dialysis in a ‘euvolaemic’ state … ie: they are NOT overloaded, and are in (or near to) volume balance from the get-go … unthinking and aggressive UF is symptomatically unpleasant, and physiologically unnecessary. These patients (and I suspect your husband may well fall into this category) suffer sorely, and their RRF is jeopardised, when fluid is sought for removal when there isn’t any excess to draw from.

My guess is that he might need either (1) euvolaemic dialysis … ie solute removal without fluid removal, or (2) even gentle fluid replacement during dialysis … negative UF, if you like. While this latter option is not uncommon, all too often, dialysis units appear to slavishly apply an UF ‘minimum’ - a minimum that is often way too high - when anything but the smallest amount of UF (if any) has been inappropriate from the start.

How much - if any - of this applies to your husband, I cannot tell, but these are general observations that may help you understand the possibilities.