CVVHDF for clearing Lactic Acid

[MICURN5280]

I had a 55/m post PEA arrest pH 6.6 and a lactate of 24 PTT >150 INR was too high to result. Temprature on arrival was 29 C. No significant neurological functions occasional myoclonic movement, pupils fixed at 4mm. CV wise SR with RBBB MAP holding 65, on epi at 1 mcg/kg/hr nor epi at 1.5 mcg kg hr and vasopressin at 0.04. A line, TLC cooling cath and we inserted a mahurker (more on that later). Pulm intubated, syncronous w the vent cxr unremarkable, no adventious breath sounds, 100% 10 of peep ABG pco2 54 Po2 90s pH 6.6 lactate 24 HcO3 of 3 GI/GU distended and firm abd 1200 out via NGT black gastric contents foley minimal UOP Hemoglobin around 7 and platelets in the 30s

lfts consistant w shock concurrent w liver hx of etoh abuse creat 3 ish

questions. MD ordered Lactated ringers for fluid boluses. Ive heard it both ways its ok to give in lactic acidosis its eventually converted to bicarb w normal liver fxn. And its NOT okay to give in lactic acidosis it compounds the issue regardless of liver fxn

started CVVHD running net even to correct acidosis after bicarb and a bicarb drip. We use the prismaflex with a M150 filter 4 k bath 2.5 ca. My filter started clotting after 20 min. I understand removing lactate and the cytokines will cause this due to the molecular size my question is if we were to switch to cvvhdf and use a pre filter replacement with the increase in hydrostatic force (solvant drag) would this help increase filtration and clearence and increase the life of my filter?

Patient re arrested shortly after i finished returning the blood and expired.

Thanks in advance for input feel free to correct me if im misunderstanding mechanisms or patho

[offlabel]

MD ordered Lactated ringers for fluid boluses. Ive heard it both ways its ok to give in lactic acidosis its eventually converted to bicarb w normal liver fxn. And its NOT okay to give in lactic acidosis it compounds the issue regardless of liver fxn

Can't speak to your other issues, but I can say emphatically, tho anecdotally, that in those circumstances where crystalloid is needed, controlling/treating acidosis is harder if you're using LR. I use plasmalyte or normosol or something like those and IMO/E the difference is demonstrable.

[PresG33]

Agree with offlabel, plasmalyte is optimal here. If only have LR or NS, LR is probably better because the SID of NS will make acidosis even worse than LR. LFTs being up were due to hypoperfusion, not liver failure so liver was still probably able to buffer lactate, usually only don't give LR for those who have chronic and endstage liver failure, not just an LFT bump. In my unit we never did the CVVHDF, but the theory is that it is better in sepsis-type patients because the high volumes of dialysate will reduce filter gunking. Last comment is that with those pressor doses and ABG, this patient was already dead, his body just hadn't realized it yet. Likely a fatal dose of shock had already been sustained and there was nothing to bring them back. Once a post arrest patient is on high dose pressors for more than a few hours they generally need to go on ECMO or they won't survive (in my experience).

[Cowboyardee]

In general use of pre-filter replacement helps limit clotting in the filter. And it does help push more large particles across the filter membrane. But I'm not so sure that it helps a filter that's clogging last any longer. And given your patient's condition, it sounds a little more likely that he was clogging the filter than clotting it (when the filter clogs, the transmembrane pressure increases substantially while the pressure drop holds steadier; in clotting, TMP and pressure drop both rise steeply).

On the upside, I've heard that a filter repeatedly clogging is really just a sign that the therapy is working as intended - those bigger particles junking up your filter needed to come off and were previously junking up your patient's bloodstream. On the downside, there's not much I know of you can do to prolong filter life in a patient with enough junk in their bloodstream to repeatedly clog the filter in such short order.

For whatever it's worth, PresG33 sounds right to me - your patient was probably not long for this world at the start of therapy.