For the past two or three weeks, we've noted a number of cases of vascular access bleeding after dialysis. The dose of the anticoagulant used not changed.
What are the possible and common reasons for this?
The two main reasons for access vascular bleeding at the end of dialysis session are either excessive anticoagulation of the session or a stenosis on the venous site of the fistula
The dose of the anticoagulant was not changed but did the bleeding events coincid with a change of the anticoagulant brand ?
The biological activity of heparin changes every batch. This is a possible explanation
In addition to what have been said, patients' medication list might need to be reviewed for anti-platelet (particularly dual) and/or anticoagulant therapy.
Dear Marc Marano,
Can you explain how it does change with each batch If the preparation's procedure, calculation has been followed and not changed ?!
Natrium heparin is an Extractive purified mixture of bovine polysaccharides with molecular weight between (I dont remember) and (again, I don't remember). Anymore different batches never have the same biological activity
May be some very trivial things like compression of the vascular access after termination of the procedure should be also considered; usually compression may be performed by the patient or nurse. Sometimes, due to high amount of work (if perfromed by nurse) of lack of compliance by the patient, the compression is not as required and postdialysis bleeding may develop. BR, Michaela
Once dismissed what you probably consider, I suggest the following reasons:
- Other medication (ATC Code B01A)
- Loss of skin and subcutaneous tissue by repeated punctures in the same place
There may be several factors responsible for prolonged bleeding from needles insertion sites after needles removal with dialysis termination: unnecessarily high anticoagulant dose during dialysis (when using unfractionated heparin, it can be found by comparing patient pre-dialysis Activated Clotting Time with its value in the blood sample taken from the arterial line at the end of dialysis - the latter should not be much higher than the pre-HD value, say 10-20% more, not higher); insertion of the needle against instead of along the flow in the vascular access; high pressure in the access due to a stenosis (it should not exeed some 20 mmHg in native AV fistulas and about double in synthetic grafts).
F. Lopot
Vascular access bleeding following dialysis could be as a result of residual anticoagulant effects. Pressure at the vascular access site should be applied until hemostasis is restored. If there is excess residual anticoagulant, protamine sulfate may be given to the patient if heparin was given as an anticoagulant. The ACTs may be performed to determine that the baseline hemostasis has been restored and then gradually the pressure can be released and the vascular access site observed for quite sometime until it is safe that the patient is not bleeding any more.
As above. Also not stopping UFH infusion early enough during the course of HD procedure. If one uses boluses - too high dose of the second one.
In many cases quite trivial - the noncompliant patient releasing pressure from the fistula, that who wants to leave the dialysis room as early as possible.
1- Excess Anticoagulation dose.
2- Access stenosis or thrombosis at the outlet.
3- Access infection Graft or Fistula.
4- Bleeding tendency from DIC, Thrombocytopenia or other coagulation defect.
I suggest the following reasons:
-revalue the dose and time of administration of anticoagulant therapy during dialysis session and if heparin assess the possibility of using unfractionated heparin shorter half-life and also by having protamine to reverse its effects
-Check possibility of proximal vascular access stenosis or thrombosis, plus proximal skin integrity in the way of the vascular access
-Assess whether the patient is taking antiplatelet drugs
-Check possibility of clotting disorders
I suggest these reasons
prolonged bleeding can be form
Not holding off properly. If the patient has been holding off, get the nurse to do it and see if the problem still occurs.
If the haemoglocin or platelets have dropped the patients anticoagulation requirements are less. You will need to check these and if they atre low reduce the dose of anticoagulant and increase the dose of Aranesp.
You will also need to check the flow of the fistual and or recirculation in the fistula. If there is recirculation and/or low flows, this is indicative of a stenosis which caused more bleeding at the end of dialysis.Ways to check for this is with atransonic device or fistulagram.
If the problem is intermittent and there are no other obvious causes, take a look at the technique for removing the needles from the access. If pressure is applied too soon, before the needle is completely clear from the skin, pressure can cause the needle to slice through the tissue and cause a larger surface area for bleeding. This can be ealisy addressed by retraining staff or by having staff remove the needle before the patient starts to hold pressure for themselves.
There are many factors responsible for prolonged bleeding as mentioned above. But, I'd like to remind the Study of the North American multicenter group ppCRRT (prospective pediatric continuous renal replacement therapy) wich did not show superiority of citrate compared to heparin in terms of durability of the extracorporeal circuit, however,has shown that the use of heparin was associated with a risk of bleeding, and one case of heparin-induced thrombocytopenia.
- retrieve a vial of heparin from the batch that you used during the time of increased bleeding and have its potency tested. Is it associated with a new tech who's technique might not be good? Yes check the PTT and PT or ACT on a series of patients to make sure you do not have a real problem or is it just bad luck.
Stenosis of venous site the commonest cause once other obvious causes are excluded
Look if there was a change in the manufacturing company of the drug you use which could change the potency of the anticoagulation drug. Although you are using the same drug different generics have different bioavailability and potency. We have noticed this once and we found our answer.