I don't think you will find and "hard" guidelines, but recommendations.
If your ultrasound has the ability to measure vessels in "mm", then you can do a simple calculation to determine a catheter-vein diameter ratio. This measuremnt cannot be used to determine the flow ratio, but it can be used to give you the ratio between the PICC and the vein. (Some ultrasounds have the ability to determine area of the vessel at the point of measurement, thus you could determine the catheter-vein area ratio.)
Nevertheless, a 6F PICC is 2mm from wall to wall. So using the simple method of diameter ratio, a 6F PICC (2mm) placed in a 6mm has a ratio of 33%. If the catheter if larger at the base, then this ratio would change. The magic question is...... what is the "ideal ratio?" In considerating this ratio, is one looking at simple diameter ratio or area ratio? Which ever ratio you choose to look at only takes into consideration one of the underlying factors for thrombosis formation, that being venous stasis. There are other reasons, also, that being hypercoagulability and endothelial damage. Perhaps with the absence or presence of the other two factors, one could have a catheter vein diameter ratio < or > than the 33%.
I wish it were "easy and one size fits all" but unfortuantely this ratio is unique to each patient. It's sort of like different strokes for different folks! LOL Hope this helps. Good luck
I am a Clinical Educator for Bard Access Systems and will gladly provide an answer to a direct question for Eric.
NO, 9 out of 10 nurses on this forum are NOT an employee of Bard. After reviewing this forum's September 2008 responses to topics I summarized the following:
Total topics posted or responded to = 86
Total responses logged = 238
Total responses from nurses = 204
Total responses from a "Bard nurse" = 19
% of responses from a "Bard nurse" = 0.9313725
I appreciate all the information posted by Kathy Kokotis and Mari Cordes (only 3 people representing Bard Access Systems posted).
I do not understand the rest of your post regarding an unsafe product and since your credentials are not posted it is difficult to ascertain if your negative experience was as a patient, clinician, or both. There are many quality vascular access products available from a variety of manufacturers, I hope you have found some to work with.
I too have posted this question and have never received an adequate response. I have searched the forum threads and downloads as Mari suggested, but have not seen a good response as of yet. I did see a chart Mari posted for catheter to vein ratio, but am searching for responses from other clinicians. I use the 33% - 50% rule (much like the example Cheryl provided) What I would like to see is examples from other clinicians (i.e. catheter size and smallest size vessel that can accomodate catheter) so that we can compile all of the information and come up with a good recommendation for all to use. I have included what I use here for catheter placement, don't know if you all will agree with the measurements I have but I appreciate any comments (good or bad as long as they are valid and not condescending). Thanks.
Cath/FR sizeMin Vessel Size3FR = 1.0 mm (.1cm).20cm - .30cm4FR = 1.35mm (.135cm).27cm - .41cm5FR= 1.67mm (.167cm).33cm - .50cm6FR = 2.0mm (.2cm).40cm - .60cm7FR = 2.3mm (.23cm).46cm - .69cm8FR = 2.7mm (.27cm).54cm - .81cm9FR = 3.0mm (.30cm).60cm - .90cmCatheter size of picc should consume no more than 1/3 to ½ the diameter of the vessel.
I would point out that we do begin to have more definitive information on this subject, as presented by Dr. Tom Nyfong at the Sept. AVA conference. His vascular pathology research has shown that a catheter that takes up 30% of the vessel (in terms of diameter measurement, NOT surface area) reduces blood flow by 30%. A catheter that takes up 50% of the vessel reduces blood flow by 70%. As stasis of blood is one of the three causes of thrombosis (per Virchow), we can see that catheter to vessel size is a significant concern in our attempts to limit thrombosis. Clearly, a catheter that takes no more than one-third of the vessel is far superior to one that takes one-half, especially in a patient with other thrombosis risk factors, such as hypercoagulability. We should consider the true size of the catheter in the vessel, meaning, consider the length and end diameter of the reverse taper, and determine if you want to insert the reverse taper into the actual vessel, based upon vessel size. Also, we should track the vessel as far as possible, to assess for potential areas of narrowing distal to the proposed insertion site. With a good ultrasound, you can visualize the vessel on most patients at least as far as the axillary, and often as far as the junction of the clavicle and first rib.
This is always a risk vs. benefit critical thinking decision.
With the taper at the hub end, isn't it even bigger than 6FR? I don't feel really comfortable putting something in that msight really be a 7 or 8 FR in the smallest part of the vein (since veins get bigger as you go up the arm). I haven't seen any published data or evidence about DVT rates that I can show to the Radiologists to get them to stop putting 6 FR PICCs with a taper all the way in in little patients. (adults - mostly elders) They put them in everyone and I have seen a lot of phlebitis (which they won't admit has a thrombus associated with it)
Perhaps you and your physicians could consider a 6F non-tapered triple lumen, if indeed you want a 6F but fear the catehter to vessel ratio would be too narrow to allow adequate blood flow around the catheter.
Please email me off of the list and I can provide you information on DVT rates with various sized catheters. I do not want to lead this thread into a "my product does this......your product does that......"
Pat - I encourage you to search around this website; there are a number of forum discussions and downloads related to this subject.
Mari Cordes, BS RN
Mari Cordes, BS RNIII VA-BC
Vascular Access Department
University of Vermont Medical Center
Are 9 out of every 10 nurses on this forum an "employee" of Bard? If you can't make a safe product for your customers, just hire them all I guess!!!!
Eric
Eric
I don't think you will find and "hard" guidelines, but recommendations.
If your ultrasound has the ability to measure vessels in "mm", then you can do a simple calculation to determine a catheter-vein diameter ratio. This measuremnt cannot be used to determine the flow ratio, but it can be used to give you the ratio between the PICC and the vein. (Some ultrasounds have the ability to determine area of the vessel at the point of measurement, thus you could determine the catheter-vein area ratio.)
Nevertheless, a 6F PICC is 2mm from wall to wall. So using the simple method of diameter ratio, a 6F PICC (2mm) placed in a 6mm has a ratio of 33%. If the catheter if larger at the base, then this ratio would change. The magic question is...... what is the "ideal ratio?" In considerating this ratio, is one looking at simple diameter ratio or area ratio? Which ever ratio you choose to look at only takes into consideration one of the underlying factors for thrombosis formation, that being venous stasis. There are other reasons, also, that being hypercoagulability and endothelial damage. Perhaps with the absence or presence of the other two factors, one could have a catheter vein diameter ratio < or > than the 33%.
I wish it were "easy and one size fits all" but unfortuantely this ratio is unique to each patient. It's sort of like different strokes for different folks! LOL Hope this helps. Good luck
Cheryl Kelley RN BSN, VA-BC
I am a Clinical Educator for Bard Access Systems and will gladly provide an answer to a direct question for Eric.
NO, 9 out of 10 nurses on this forum are NOT an employee of Bard. After reviewing this forum's September 2008 responses to topics I summarized the following:
Total topics posted or responded to = 86
Total responses logged = 238
Total responses from nurses = 204
Total responses from a "Bard nurse" = 19
% of responses from a "Bard nurse" = 0.9313725
I appreciate all the information posted by Kathy Kokotis and Mari Cordes (only 3 people representing Bard Access Systems posted).
I do not understand the rest of your post regarding an unsafe product and since your credentials are not posted it is difficult to ascertain if your negative experience was as a patient, clinician, or both. There are many quality vascular access products available from a variety of manufacturers, I hope you have found some to work with.
Timothy L. Creamer, RN
Regional Medical Center Bayonet Point
Clinical Educator, Bard Access Systems
Timothy L. Creamer, RN
Clinical Specialist, Bard Access Systems
patricia,
I too have posted this question and have never received an adequate response. I have searched the forum threads and downloads as Mari suggested, but have not seen a good response as of yet. I did see a chart Mari posted for catheter to vein ratio, but am searching for responses from other clinicians. I use the 33% - 50% rule (much like the example Cheryl provided) What I would like to see is examples from other clinicians (i.e. catheter size and smallest size vessel that can accomodate catheter) so that we can compile all of the information and come up with a good recommendation for all to use. I have included what I use here for catheter placement, don't know if you all will agree with the measurements I have but I appreciate any comments (good or bad as long as they are valid and not condescending). Thanks.
Cath/FR size Min Vessel Size3FR = 1.0 mm (.1cm) .20cm - .30cm4FR = 1.35mm (.135cm) .27cm - .41cm5FR= 1.67mm (.167cm) .33cm - .50cm6FR = 2.0mm (.2cm) .40cm - .60cm7FR = 2.3mm (.23cm) .46cm - .69cm8FR = 2.7mm (.27cm) .54cm - .81cm9FR = 3.0mm (.30cm) .60cm - .90cmCatheter size of picc should consume no more than 1/3 to ½ the diameter of the vessel.sorry guys, my copy and paste didn't work right, here it is again
Cath/FR Size Min Vessel Size
3FR = 1.0mm (.1cm) .20cm - .30cm
4FR = 1.35mm (.135cm) .27cm - .41cm
5FR = 1.67mm (.167cm) .33cm - .50cm
6FR = 2.0mm (.20cm) .40cm - .60cm
7FR = 2.3mm (.23cm) .46cm - .69cm
8FR = 2.7mm (.27cm) .54cm - .81cm
9FR = 3.0mm (.30cm) .60cm - .90cm
Catheter size of picc should not consume more than 1/3 to 1/2 the diameter of the vessel.
found my answer
Which line should be used for the drug Cubicin ML or PICC.
I would point out that we do begin to have more definitive information on this subject, as presented by Dr. Tom Nyfong at the Sept. AVA conference. His vascular pathology research has shown that a catheter that takes up 30% of the vessel (in terms of diameter measurement, NOT surface area) reduces blood flow by 30%. A catheter that takes up 50% of the vessel reduces blood flow by 70%. As stasis of blood is one of the three causes of thrombosis (per Virchow), we can see that catheter to vessel size is a significant concern in our attempts to limit thrombosis. Clearly, a catheter that takes no more than one-third of the vessel is far superior to one that takes one-half, especially in a patient with other thrombosis risk factors, such as hypercoagulability. We should consider the true size of the catheter in the vessel, meaning, consider the length and end diameter of the reverse taper, and determine if you want to insert the reverse taper into the actual vessel, based upon vessel size. Also, we should track the vessel as far as possible, to assess for potential areas of narrowing distal to the proposed insertion site. With a good ultrasound, you can visualize the vessel on most patients at least as far as the axillary, and often as far as the junction of the clavicle and first rib.
This is always a risk vs. benefit critical thinking decision.
With the taper at the hub end, isn't it even bigger than 6FR? I don't feel really comfortable putting something in that msight really be a 7 or 8 FR in the smallest part of the vein (since veins get bigger as you go up the arm). I haven't seen any published data or evidence about DVT rates that I can show to the Radiologists to get them to stop putting 6 FR PICCs with a taper all the way in in little patients. (adults - mostly elders) They put them in everyone and I have seen a lot of phlebitis (which they won't admit has a thrombus associated with it)
Eve - KY
Perhaps you and your physicians could consider a 6F non-tapered triple lumen, if indeed you want a 6F but fear the catehter to vessel ratio would be too narrow to allow adequate blood flow around the catheter.
Please email me off of the list and I can provide you information on DVT rates with various sized catheters. I do not want to lead this thread into a "my product does this......your product does that......"
Cheryl, aka fruitloop
Teleflex
Cheryl Kelley RN BSN, VA-BC
Forgot the address
[email protected]
Cheryl Kelley RN BSN, VA-BC