I was requested to find the EB literature on why we do not do BP's on arms with PICCs. I can not find it in Standards or the Infusion Nursing textbook except the section where contact of epithelial layer of vein against the catheter can disrupt this layer and cause thrombus.
Would this be sufficient?
Chris Thomas
That is your evidence. Anatomy and physiology is evidence. How would we actually do a study on this question? Would you set up a group of patients with BP checks on the arm with a PICC and BP checks on the arm without and measure what? Phlebitis, lumen occlusion, thrombosis? If we have A&P knowledge that indicates a higher risk in one group, no IRB would ever allow such a study for ethical reasons. We will never be able to have studies to address every single solitary issue and this is not the purpose of EBP. Sorry for my soap box but this approach to EBP of requiring a study for everything simply makes me crazy. 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
Anatomy and Physiology provides us with the basis for a theory on this question but not evidence. Theory is what comes before evidence, and scientifically speaking it's essentially blasphemy to say the two are equal. There is no reason why an IRB board would not approve such a study. Nearly every study in existence began with a theory that one way of doing something might be better than another, that's why we do them, because theory is just theory and proves nothing until there is evidence to support the theory. Studies are still done even when there is not just theory, but even when we already have some evidence that one method is more harmful than another. Although that doesn't mean that evidence has to be based on randomizing people into a control group where theory would suggest they will experience poorer outcomes, that's why we also look at retrospective studies.
Theory does not make EBM. We often include recommendations based on solely on theory in Evidence based (more accurately called Best practice) recommendations, but only with the disclaimer that there is no actual evidence to support the recommendation. More serious EBP groups won't even comment on an issue without sufficient evidence, regardless of the theory involved, in order to avoid mixing the two.
Perhaps I should have said "pathophysiology" then. We know that contact between a plastic catheter and the endothellial cells of the tunica intima, the internal layer of all veins and arteries, will cause disruption of that layer. This disruption has been proven to produce immediate thrombus development along with inflammation due to contact between the blood and basement membrane exposed with this disruption. With this knowledge, I do not believe that any IRB would approve such a study. If I were asked to participate in such a study, my immediate reply would be no. My point is there will always be questions that are unsupported by evidence and it is not possible or feasible to wait for such evidence to be produced. We must combine our knowledge of A&P, infection prevention principles, etc to make the best patient care decisions today. So there are no studies available on the original question, but there are lots of studies showing the pathophysiology of thrombus development. Those must be applied to answer this question. Also, you should check the Infusion Nursing Standards of Practice as we added a level of I A/P and this is defined as "includes evidence from anatomy, physiology, and pathophysiology as understood at the time of writing." So A/P information is used for evidence. In hindsight, I can now see many areas of the standards document where the committee could have used this level much more than we did. 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
Thanks for the info and actually the dialogue was very interesting. I am regarded as one of the infusion nursing/vascular access experts, or should I say, more knowledgeable on this field than most people in this part of the country and I give EB info and resources to confirm questions on a daily basis.
Sometimes, however, I have to agree with Lynn. Constantly trying to find a study on things can be wearing on me, especially when dealing with large medical systems that think that if they don't study it, it can't be true. :)
It has lead me to multiple battles to establish best practice and empower nurses. Thanks to research, anatomy and physiology, INS, AVA, Lynn Hadaway, Nancy Moureau, Kathy Kokotis, Galloway, Marcia Ryder, etc. etc. etc., I usually win the battles. The great articles, programs, Standards, evidence-based research and dialogue with all these experts have been the wings beneath my wings even going against some pretty powerful people.
Until I get fired or retire,
Thanks to all of you
Chris
Thanks Chris, I don't think you will get fired!! 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