Forum topic

 No, it would not be wrong to include this practice in your policy simply because it is not in the INS standards. However I would add that there are no other standards or guidelines that recommend its use. This practice got started from nurses sharing anecdotal experiences and there is no evidence to support it use. How much is your hospital using and relying on evidence for your policies and procedures? The Flushing and Lockin standard was one I especially worked on and I did not find any supporting evidence, thus this practice was not included. There is some evidence that it might increase the breakage of biofilm which could increase the risk of BSI. Please note "might" and "could", again no strong evidene for this either. Biofilm literature includes evidence about shear forces causing the breakage of bioflm. This technique could create excessive shear forces which could break the biofilm where it floats into the bloodstream and produces BSI. So, I think the approach you choose is based on your hospitals emphasis on evidence based practice. Lynn

 (However I would add that there are no other standards or guidelines that recommend its use.)

http://www.rcn.org.uk/__data/assets/pdf_file/0005/78593/002179.pdf

Royal College of Nursing

The RCN IV Therapy Forum

6.2 Maintaining patency

Third edition, January 2010

Standards for infusion therapy

It’s a bit of a stretch (for me) to assume more shear force ( intralumen fluid movement ) is created with a gentle pulsitile (push pause), then regular accessing a lumen with a straight flush. Especially in light of what was evidenced with PICC catheter movement  in the Navilst/ Manly in vivo porcine test/experiment.

 Your Goodwin and Carlson reference did not provide any science to support this practice and neither did the Gabriel article you mentioned. 

I also think you misunderstood my point about shear force. I am saying that the turbulent flushing technique may create a high shear force that could cause biofilm to break. This does not address infusion-induced catheter movement that Lynn Manly's work was assessing. We have to compare apples and apples here. There could be 2 problems associated with flushing technique

1. infusion induced catheter movement, the term coined by Dr. Greg Schears work which was also associated with the work done by Lynn Manly. This is discussion in the online CE course we offer, The Perils of Power Injection. 

2. the turbulence created with the push-pause flushing technique could cause biofilm to break and might increase the risk of BSI, however this is only based on biofilm research and has not been studied in relation to catheter flushing technique. 

Until we have some science supporting positive outcomes with this turbulent technique, I do not teach it nor support its use in any way. It came about solely based on anecdotal experience which is very far afield from the evidence-based practice being emphasized today. 

Lynn

I was going to start a discussion about biofilm, catheters and flushing as it pertains to laminar, transitional and turbulent fluid dynamics. I would also like to see the studies performed for an evidence based laminar flow flush. To my knowledge a laminar or steady flush is also anecdotal. But I think I'll just quote Marcia Ryder the biofilm expert and agree with her and I'll agree to disagree with Lynn on flushing technique.

http://www.iv-therapy.net/node/1829

" Blood clearance from catheters is also essential in that the presence of thrombus has been well documented as correlative to CRBSI.  Turbulent flushing is readily observed to clear blood from tubing compared to laminar flushing.  We have NO evidence at this point to direct us in any alteration of current practice of flushing techniques especially in relation to biofilm. To imply that turbulent flushing should be reconsidered due to biofilm detachment is making a huge leap and may lead to an increase of other risks associated with poor flushing.  Biofilm will themselves actively detach and disperse clumps and cells even in low shear. "

Marcia Ryder PhD RN

Research Coordinator, USC Center for Medical Biofilm Research
 

 I think this thread has brought up 2 different situations and we are trying to compare apples to oranges. The first would be the need to immediately flush in whole blood after it has been withdrawn into the catheter. This would be what the post was referring to on arterial blood. I would agree that you can get more of the whole blood flushed back into the catheter immediately after you have withdrawn it by using this stop-start method. We have anecdotal evidence as described in that post. We do not have true empirical evidence to support this, but it is easy to see that all visible blood can be flushed back into the catheter. There could easily be blood proteins that attach to the catheter wall though. We know that these proteins begin attaching within 5 minutes of blood exposure to the catheter and the catheter can be completely coated with a fibrin sheath within 24 hours. So the quicker you flush the blood back in, the more likely you are to remove more of it. I would hasten to add that there is evidence that there can be 1 million RBCs present without a change in color, so you will not see the red in the tubing but there are still blood products present. 

The second situation and the one where I say this technique is not effective, is when blood has been allowed to reside within the catheter lumen for a longer period allowing fibrin to attach. I have seen written hospital policies stating that this stop-start technique will "clean" the catheter walls. This is wrong information. There is no evidence that this flushing technique can remove serum proteins that are adherent to the catheter wall and therefore this technique is probably useless. There is no evidence to support this theory of cleaning the catheter walls, yet this myth continues. So perhaps our diagreement is not really a difference at all because we are talking about 2 separate things. 

Lynn