Use of Heparin on PD

Whats the best way to know if fibrin exists?
Drain bags on PD show no signs of fibrin by the morning.
We’re having to look 1st and 2nd drain.
Or allot of slow flows.
We waited too long bc the drain fluid was clear and fibrin built up around tube. Had to have surgery 2 times bc Dr didnt put Mike on heparin so ive had to do research myself.
Last but not least …
How is it heparin does not get absorbed on PD and how is it neutralized?
Would love to learn more about the use of heparin.
Thanks for any help

Dear cmbyrd60

Almost all PD patients will intermittently pass small wisps of fibrin in their PD effluent - the drainage fluid - and, sometimes, even larger semi-translucent, transparent ‘floaters’ that look a bit like a small jelly-fish. While this is normal, some patients form more fibrin than others, and the fibrin can also occasionally plug, block, or envelope the Tenckhoff catheter, causing real strife with either slow and/or intermittent drainage, or complete obstruction of the catheter. Fibrin is also more common in the aftermath of an episode of peritonitis, a period where some PD experts like to add some heparin to diminish or prevent fibrin formation and to keep the catheter patent (open).

The dose of heparin that is added to the PD bags varies from service to service … from 500 units of heparin per litre of dialysis fluid and right up to 2500 units/litre.

Why the dose variation? Well, to be honest, there is no good reason ‘why’ that I can give - except that practice varies.

A University of Missouri study by Gries and others [and U Missouri is a widely acknowledged ‘guru centre’ for PD] showed that 500 units per litre is just as good at preventing fibrin formation as are the higher doses. In our unit it has been our practice to use 1000 unit per litre of dialysis fluid.

Whatever the local practice is, the amount needed to inhibit the formation of fibrin is was, way too little to be significantly absorbed into the circulation and thus affect blood clotting mechanisms. The effect of additive heparin to PD fluid is restricted to an intra-peritoneal action… i.e. it only works on the fluid contained within the peritoneal cavity alone, and not elsewhere in the body. Heparin is a large molecule and is negatively charged - and both are characteristics that prevent significant absorption across the peritoneal membrane. So … you shouldn’t need to be anxious about any significant absorption or about any problems with bleeding.

While it is common to say that there are no known ‘down-sides’ to the addition of heparin … and most would suggest it is added freely in those patients who are either fibrin-makers (again, some do more than others) or have a current or had a recent episode of peritonitis … I would add one exception to my ‘no known downsides’ comment … the ever-present risk of introducing infection. Whenever something (anything) is added to a bag of peritoneal fluid, the sterility of the bag is potentially breached. While when additives (like heparin) are added correctly and carefully, this risk is miniscule, it remains a possibility. So, a sterile technique is essential when adding heparin. All/any patient can be taught this - there is NO reason why a nurse or doctor can do this any better than a well taught, careful patient - but note my emphasis on ‘well taught’ and ‘careful’!

Learn to inspect your drainage bags. A few ‘wispy threads’ are common and no cause for anxiety but a ‘jelly-fish’ can be a bit more concerning.

A good and competent training team should teach you all this stuff as part of routine PD training. Take note of their training … and you shouldn’t go too far wrong.