Preventing Extracorporeal Clotting in the Acute Setting

[westieluv]

I am getting pretty comfortable in the acute HD setting, but I still worry about clotting the dialyzer during each tx. It has only happened to me on a handful of occasions, and my more experienced co-workers assure me that it happens to them too, that sometimes it just can't be prevented, but do any of you have any tips that would help to prevent it from occurring? I know how to increase my UF goal and then flush with NS liberally to compensate and prevent clotting, but sometimes I don't like to do that, especially if the pt is trending very hypotensive during the tx. We don't use heparin in our acute setting, so what else can I do to make sure that extracorporeal clotting, and the subsequent restringing of the machine, is less likely to happen?

[MendedHeart]

What about Agratroban?

http://www.ncbi.nlm.nih.gov/m/pubmed/15632219/

http://www.ncbi.nlm.nih.gov/m/pubmed/17103051/?i=4&from=/15632219/related

[Chisca, RN]

Both of those articles on argatroban reference patients with known HIT, one in the setting of CRRT. CRRT treatments run continuously, ie 24 hours unlike hemodialysis where the treatment is 3-4 hours. Clotting of circuits during CRRT is common problem due to the length of the treatment. On the other hand once you have HIT you have to have some way of preventing further clotting hence the need for argatroban until coumadin therapy can be established. I have only seen this drug used once the diagnosis of HIT was established.

[Chisca, RN]

I was looking at the web page for Rexeed filters as we use these when a patient is allergic to the Fresenius F180. Came across this interesting statement:

"If platelets directly touch a membrane surface, it is possible to stimulate platelet aggregation, leading to platelet adhesion to the membrane surface. The coagulation system is also highly susceptible to such activation. The hydrophilc gel layer on the inner membrane surface of the REXEED filter is designed to cushion the platelets and other blood components from activation caused by blood membrane interaction."

http://www.asahi-kasei.co.jp/medical/en/dialysis/product/rexeed-series/feature03.html

[Chisca, RN]

One of my patients yesterday was admitted with a GI bleed but also had a history of clotting his circuit during treatments. He always needed heparin and insisted we at least prime the circuit with heparin but the doctor wasn't going to risk further bleeding. The patient felt he would also lose blood if he clotted so we compromised on saline flushes but then I thought why not a continual infusion? The doctor agreed and so I ran normal saline at 200cc hr through the arterial side, added the 700cc saline to the total UF removed ( 710 ml/hr UF rate) and it worked well, the circuit did not clot. I showed the patient the filter and circuit afterwards but he couldn't really say if there were less clots. This might be an option for those prone to clotting where heparin can't be used. I did find an article afterwards that discussed continuous verses intermittent flushing. I can't get the link to work but the title is " Intermittent saline flushes or continuous saline infusion: what works better when heparin-free dialysis is recommended? ", Authors: Zimbudzi E, April 2013 Dove Press Volume 2013:6 pgs 65-69.[h=1][/h]

[Chisca, RN]

Priming the circuit with albumin before the treatment might help in those patients that you know are prone to clotting. The albumin carries a negative charge and readily coats the plastic surfaces preventing platelet aggregation.

Investigation of Platelet Responses and Clotting Characteristics of in situ Albumin Binding Surfaces

[gollybabbler]

Very good info here, thanks to all. I would just like to add that I've kept track of certain statistics since I started in dialysis (over 2500 patients served!) and the clotting rate is about 10%- we do not prime with Heparin and boluses are rarely ordered. A sister group does not even use Heparin in their catheters any longer.

[NurseRies, BSN, RN]

Very good info here thanks to all. I would just like to add that I've kept track of certain statistics since I started in dialysis (over 2500 patients served!) and the clotting rate is about 10%- we do not prime with Heparin and boluses are rarely ordered. A sister group does not even use Heparin in their catheters any longer.[/quote']

Interesting. After doing dialysis in different parts of the country , I've noticed that some ethnicities have a tendency to clot more then others. Has anyone noticed that? I have also worked places where they don't pack the caterers with heparin and had no problems with clotted catheters. I have worked other places where packing with saline just one time was a huge deal! Don't know if there is a lot of research on this topic. The Tego cAps are supposed to prevent clotting, not to mention less risk. Have you ever heard of someone bleeding out from the ED pushing their 5000unit/ml heparin Into their catheter for urgent IV access? I have.

[Chisca, RN]

TEGO caps have a design flaw that I don't like in that the thread for the leur lock is not complete, it is two little nubs that the tubing threads on. This can easily become disconnected under pressure so you have to use a second safety clip to keep it in place. Poor design. I still pull clots out of these catheters but we only use saline flushes in 20cc amounts. I have seen 4% citrate used as a lock on someone who was allergic to heparin and it worked well but the pharmacist sometimes doesn't know what you're asking for. I find the blood loss patients experience during dialysis to be troubling but there seems to be an acceptance of this blood loss as a risk of therapy. A decade ago there was a study of blood loss in ICU pts from daily lab draws and it was estimated to be 200 to 300cc a week. That's enough to require a blood transfusion. How much more is a dialysis pt losing with 3x week treatments?