Albumin

Dr. Agar: Please explain the appropriate use of albumin during a hemodialysis treatment. Many nephrologists are against giving albumin. If a patient’s albumin is low and fluid removal is an issue, why not use albumin?

Dear Barbara

Yes, we not uncommonly use adjunctive intra-dialysis albumin to assist in moving compartmentally ‘locked’ fluid where the albumin level is mid-low 20s or less and, by compartmentally locked, I mean fluid that has become inaccessible to the intra-vascular space and thus dialysis removal.

I did a patient webinar some years back for Dori at HDC on fluid in dialysis and about how the 3 basic body fluid compartments interact with each other: the intracellular compartment, the extracellular extravascular (or interstitial) compartment and the intravascular compartment. If you have access still to this, it might be helpful to sit down and listen through it.

In essence, though, albumin is a major body protein - one that circulates in the blood stream = the intravascular compartment and is responsible for 'attracting and holding fluid (ie: salt and water) inside our blood vessels (ie: maintaining our blood volume). Albumin is vital to sustaining the blood volume … and, with it, the blood pressure.

Without adequate albumin levels in the blood stream, fluid will leak out of (extravasate from) our blood vessels into the interstitial space … the tissues of the body outside and around our blood circulation … and result in the retention of fluid in the wrong bits! The blood volume is reduced and, in turn, as the circulating blood volume diminishes, the cardiac output will fall and the blood pressure will eventually fall, too.

But, at the same time, the tissues become wet and overloaded, the tissues of the body swell with excess fluid (including the lungs - pulmonary oedema: the legs and peripheries - peripheral oedema: and elsewhere) but yet, at the same time, the intravascular volume is low (or contracted). Put simply, our bodily fluids get all screwed up with too much in the tissues and cells, and not enough ‘inside’ the circulation.

Albumin is the body’s way of keeping enough of our body fluid inside the blood vessels to sustain the blood volume.

The albumin levels can fall in several ways. Importantly, in many kidney diseases - especially in the types of glomerular disease (loosely called nephritis: though there are many different types of nephritis) and in diabetic kidney disease - the millions of tiny filters inside the kidney (the glomeruli) leak protein … and, especially, lots of albumin. This albumin is lost in the urine (albuminuria) and this overwhelms the capacity of the liver to make enough albumin to replace the losses, and the blood albumin falls. In this case, giving IV albumin provides only a temporary relief as any given IV soon leaks straight out again into the urine and away. Using albumin in this case provides, at best, some brief relief but can be useful sometimes, if but to gain control. But, this is a circumstance where using albumin is, at best, only briefly helpful (unless at the same time the urinary leak can be stopped by treating the cause).

The albumin can also be low in some liver diseases where the manufacture of albumin by the body is reduced.

Albumin is a key indicator of nutrition, and if nutrition is poor, the albumin level will eventually falter and fall … again, leading to a low circulating albumin level and the consequences above.

In dialysis, though … where albumin losses from the kidney effectively diminish to nil as native kidney function diminishes to nil … giving IV albumin does NOT lead to only a transient rise in the blood albumin level as there is no ‘leak’ left to lead to excess losses. Here, albumin can be a vital and effective way to (1) restore blood volume (2) ‘suck’ or attract fluid back into the circulation from wet and overloaded body tissues (3) improve cardiac function, and - at least to some extent - to restore nutritional status.

It is best given on dialysis so that the ‘returning’ fluid volume from the tissues does not overload the circulation but can be removed as it returns by ultrafiltration. Otherwise the circulation can flood with the fluid attracted back into the circulation by the added albumin.

We use this ‘trick’ not infrequently. When we give IV albumin on dialysis, we usually use a concentrated albumin preparation = 100 ml x 25% salt-poor albumin x (usually) 2 bottles/dialysis x anywhere from 2-4 consecutive dialysis runs if or when the albumin level is in the mid-low 20s or less AND there is a clinical mis-match in compartmentally volumes … ie: too much fluid volume in the tissues and not enough in the circulation … that we need to correct.

It’s an easy trick. It’s a good trick. It is a trick that works and gives good results. But, it IS a form of window-dressing! It does NOT treat the reason why the albumin was low in the first place. That, too, needs management and correction -else the albumin will just dwindle down again. There needs to be parallel nutritional care, addressing and stopping any albumin ‘leakage’ states ( and PD is one such potential source of protein loss) etc etc etc …

But … use IV albumin in HD patients +/- matched ultrafiltration? … you betcha!

That said … the circumstances for its use need to be understood and the advantages need to be weighed … and it is NOT for every situation. But the disadvantages are few (if any) - provided correspondingly balanced volume management on dialysis is achieved. It’s not costly, it doesn’t hurt, it isn’t associated with ‘allergic’ responses … and it works, if the situation is properly picked and it is used with the right intent and for the right reasons.

And … one final plug, here, for longer slower dialysis … this is a ‘trick’ that does not bear ‘rushing it’!

This kind of stuff needs to be done gently, slowly … it is NOT wise, sensible or right to ‘whack it in, and rip it out’. That is never, ever, the way … yet dialysis ‘maneuvers’ seem so often to be done that way - thoughtlessly and with little understanding of what is being done. Ah me …

Hope that helps.