I attended a webinar in the past year and a half and recall them talking about turbulent flushing causing biofilm to shear off the catheter and potentially causing a CLABSI. Do you have nay references on this technique?
Melanie Cates RN MSN ENC(C)
Nursing Practice Leader
Thunder Bay Regional Health Sciences Centre
I am only aware of one lab study from Europe. I have never seen any clinical studies of this technique. It is not included in the INS Standards because there is no evidence to support its use. Breakage of biofilm and fibrin is a major concern and the theory is that this is possible. But no studies for or against its use. I do not teach or support its use. Additionally, it could cause a small CVAD to have a tip migrate to another vein. Forceful injection and tip migration is documented with power injection in radiology. Turbulent flushing could, if the nurse's hand is strong enough, cause tip migration. We just do not have enough knowledge about this technique to rely upon it as many do. Lynn
Lynn Hadaway, M.Ed., RN, NPD-BC, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
I just saw that the current Plumer's P&P does recommend using "push-pause" flushing "to create turbulence" when flushing central lines. No specific reference is cited. I wonder where this practice originated if there is no evidence demonstrating its safety or benefit. The theoretical risk seems valid, but here we have a major, industry-level publication supporting the practice. I remember Paul Blackurn trying to discourage the practice 2 years ago at an ins meeting in Maryland. It didn't generate a lot of discussion. I think a lot of people just kept right on doing it!
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
Great questions! This practice began in the late 1980's I think. It was one of those strange aspects of nursing where people start talking about suggestions for solving clinical problems. Remember this was long before the emphasis on and attention to evidence based practice. It took on a life of its own. I will take a look at Plumer's and discuss it with the authors. Do you recall what chapter it is in? Lynn
Lynn Hadaway, M.Ed., RN, NPD-BC, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
I found it in Chapter 14 page 376. It's in the new 2014 Ed. I'd love to hear what you find out.
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
ONS Access Device Guidelines (3rd Ed) also states, "Flush all VADs vigorously using pulsating technique (push-pull motion) with 10-20ml of normal saline after infusing or withdrawing blood." On an unrelated topic, (but discussed earlier in the group) ONS has a guideline that states, "Valved catheters or catheters with PASV do not require clamping if valve is functioning properly. Clamping will damage the catheter." Obviously, no specific mention of preventing air embolism. There is no citation given for either of these guidelines. Yikes! I guess this is why we have discussion groups!
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
The ONS Guideline does state that clamps are used to prevent air embolism. I should have read it more thoroughly. So, ONS says that while clamping prevents air embolism and blood backflow, it is not required on valved or PASV catheters since clamping these lines will actually damage them.
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
Technically I don't think that is a correct statement about catheter damage. I think it is the manufacturers way to emphasize the difference between a catheter with an integral valve and one without. It is possible that the valve in the hub could interfere with the valve somehow. I have to take a look at the IFUs for these catheters. I am most concerned about the claims that are and are not being made regarding VAE from the catheter manufacturers. If they do not state anything regarding prevention or reduction of the risk, I would not want to accept all liability by leaving them unclamped. Remember your facility will not be paid for treating VAE now. Lynn
Lynn Hadaway, M.Ed., RN, NPD-BC, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
I thought it seemed like quite a stretch to conclude that clamping a PASV catheter would damage it. I surprised to see it in a recent ONS publication. Some of the variations in practice that manifest as topics in this infusion discussion room might come from slight deviations in recommendations from ONS among other organizations. What I'm gathering from this discussion is that practice guidelines must be compared to manufacturer's IFUs and a conservative compromise should be concluded.
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
The effectiveness and safety of "Push-pause" flushing is actually based on the well establishsed physics of how fluid flows through a tube, which is why it's often recommended including by manufacturers such as Bard.
Push-pause flushing does not actually create turbulence, rather it's how the full cross-section of a lumen can be flushed without using turbulence. Creating turbulence is determined by velocity, and with push-pause flushing the peak velocity is no different than with a continuous flush, and the shear stress along the walls is also no different than with a continuous flush.
Fluid does not flow through a tube as though there is a plunger behind, moving fluid near the wall of the tube downstream just as effectively as fluid at the core of the lumen. Shortly after starting a flush with a sustained flow, it is primarily the fluid at the core of the lumen that is flowing with gradually decreasing flow as you move out to the wall of the lumen, with almost no flow downstream at all up against the wall of the lumen. Each time you stop the continuous flush flow it allows the fluid near the wall of the lumen to diffuse towards the now flushed center of the lumen, restarting the flush then moves that diffused fluid downstream, stopping again alllows more of the fluid you are trying to flush to diffuse towards the center so that it can be flushed downstream, etc, etc.
This does relate to biofilm but only in that failing to properly flush the potential building blocks of biofilm away from the walls will be more likely to allow it to form, but it adds no additional "scrubbing" forces that would cause it to break free if it did form.
For nurses who use devices that are clear, such as a VAMP on a pressure line, the difference between the two (continuous vs push-pause) becomes evident, I generally find I don't have to suggest a push-pause technique when using a system where you can actually observe the effects of the two methods when flushing something visible (blood), nurses tend to figure out fairly quickly that a push-pause technique is much more effective.
I think the MSN candidate in me just found his thesis! This very enlightening albeit in vitro understanding of laminar vs turbulent flow really needs to be evaluated in the in vivo setting. The fact remains that regardless of the well-understood physics of line flushing, there does not appear to be consensus on the evidence-based recommendation for the proper technique for flushing a CVAD inside of a human being. Since both push-pause technique and steady flush technique have support in literature, it doesn't seem like it would be difficult to get this sort of study through an IRB!
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
We definitely need more studies on this issue. My questions include:
1. What is the effect of various flushing techniques on the development of intraluminal biofilm?
2. What is the effect of various flushing techniques on mature biofilm?
3. What is the effect of various flushing techniques on fibrin layer?
4. What is the effect of various flushing techniques on CVAD tip position?
5. What is the outcome of catheter patency when pulsatile flushing techniques are used when compared to other techniques?
I think this will require both in vitro and in vivo testing and maybe ex vivo also.
Good luck, Lynn
Lynn Hadaway, M.Ed., RN, NPD-BC, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
Dead horse...please humor me. The IFU for Angiodynamics Xcela PICC with PASV specifically recommends using "pulse" or "start-stop" technique when flushing. Are there issues with running a comparison trial looking at different flushing techniques if the IFU already calls for a specific technique?
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
That would be a question and discussion for the IRB reviewing your research plan. Flushing against high resistance can lead to catheter damage but even pulsatile flushing must stop if resistance is felt. I think this has been added to these IFU's in a copy cat manner. Much content from IFU's of product coming through the 510(k) process is virtually the same instructions, so it seems that one manufacturer copies the others. Lynn
Lynn Hadaway, M.Ed., RN, NPD-BC, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
I checked with one of the author's of the chapter you referenced in Plumer's Principles and Practices of Infusion Therapy, 9th edition. This language was changed in other parts of the book to "vigorous" flushing. Leaving this language of push/pause flushing was an overcite. Lynn
Lynn Hadaway, M.Ed., RN, NPD-BC, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
Thank you for following up on this. I am still not sure what exactly is meant by vigorous flushing. Is it still meant to create turbulence? I keep hearing from many clinicians that the effectiveness of flushing is determined by how well the technique is able to clear a needleless connector (of course an impossible task with an opaque connector). I was recently directed to CDC's 2011 Basic Infection Control and Prevention Plan for Outpatient Oncology Settings. It recommends the use of vigorous flushing using pulsating technique.
This topic has taken on a life of its own for me. It is a practice that everyone seems to be preaching, but nobody has ever studied it. It just sounds good. I actually had an expert tell me that the technique "has been proven effective even though it is not well studied or documented in literature." HOW HAS IT BEEN PROVEN, THEN???
Sorry for shouting! Have a great day everyone!
Keith W. Gilchrist, MSN, RN, PHN, OCN, CRNI, VA-BC
Oncology Nurse Navigator, David Grant Medical Center
Travis AFB, CA
Keith, welcome to my world. I have been shouting about the absence of evidnence on this issue for many, many years! We definitely need research to answer these questions and it is totally lacking. Application of fluid flow theory is one step. It can be seen in a river, stream and in the normal bloodflow. But how does this theory apply to the environment of an intraluminal IV catheter? What impact does it have, positive or negative, on the outcome of catheter patency, biofilm development, biofilm breakage and BSI. These are all unanswsered questions. It has taken on a life of its own. I would agree that absence of evidence is not evidence of absense. All I want is clinical studies on this issue to demonstrate its pros and cons. I suspect there are far too many variables to control to ever get useful clinical data. Then there is the issue of catheter tip migration due to flushing techniques, mainly coming from radioloogy and it is clinical data. Lynn
Lynn Hadaway, M.Ed., RN, NPD-BC, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
y'all can split that hair 5 ways, I just praise God the line is getting a flush :)