Steve

General monthly bloods u + e's .

Hi ,

thanks for the reply although I'm already fully aware how to take bloods pre and post haemodialysis . My initial query was solely directed at haemodiafiltration . I wanted to know if the hdf and the large volumes of online substitution fluid would in any way influence my post treatment blood result . If so what would the course of action be to obtain a correct sample . Would taking the machine out of hdf mode and putting back to normal haemodialysis be a solution ?

I think we need a definition of terms. From the difference in the spelling of hemodialysis my guess is you are not practicing in the USA. How and when exactly are you doing HDF? The only time I have seen hemodiafiltration mentioned is with CRRT and then it is referred to as CVVHDF. Since CRRT is typically a 24-72 hour therapy done in ICU, lab is drawn frequently and adjustment made as needed. For our CRRT patient's, lab is only drawn from a central line or A-line. We don't consider the replacement fluids infusing pre or post filter as having impact on the systemic lab drawn from the patient. What are you using for replacement sol? I would think lab drawn from the patient other then the dialysis circuit would be an accurate reflection of the pt's lab values and should be treated as such.

Hi thanks for the feedback . You are right I don't practice in the states although I have practised in a few different countries in the last few years . Heamodiafiltation is very common now days it combines both diffusive qualities of dialysis and the convective qualities of haemofiltration . It provides much better clearance of larger weight molecules such as B2M , it also provides better cardiovascular stability whilst being treated . The online fluid is generated from dialysate concentrates and water which goes through three ultrafilters in the machine to ensure no endotoxin contamination . The treatments are the same as dialysis in terms of time , pump speeds etc. Although the dialysate flow should be increased as the substitute fluid is diverted from there , anywhere between 9-50litres a session are used and the fluid administered pre or post dialyser . Most units have been using HDF for a few years now especially for patients who have been on dialysis for a few years and no transplant imminent . If cost is not a problem I know of units where every patient is treated using HDF .

I spoke with my Acute program Medical Director and said he had read of doing Hemodiafiltration in chronic units in other countries but wasn't sure how it was done. His question was much the same as mine in How do they do it? How do you give that much replacement sol during tx? How long are is the tx? What kind of filter do you use? Sorry I can't help but it would be interesting to learn how it is done.