Today, in a group discussion regarding flushing of Solo PowerPICCs, the question came up, "How much pressure may be exerted against the plunger when flushing a Solo PowerPICC with a 10cc syringe?" We were told by a product rep that any amount of force/pressure can only result in less than 25psi at the tip of a 10cc syringe, so if a Solo PowerPICC can withstand up to 300psi, a significant amount of pressure may be exerted without concern regarding catheter rupture. Question 1: Is this accurate information?  My concern is related to psi and the possibility of dislodging a clot or fibrin sheath, not just rupturing a catheter. Question 2: Is the 10cc syringe self-limiting with regard to amount of pressure at the tip relative to the amount of pressure being exerted against the plunger? Thanks for sharing your physics and clinical expertise.
Susan,
Your concern regarding the "possibility of dislodging a clot or fibrin sheath, not just rupturing the catheter" is very realistic. SOLO instructions include verifying patency prior to power injection procedure. Definition of a patent catheter is not only ability to flush but also includes ability to obtain blood return upon aspiration. Even a sluggish flush indicates some degree of occlusion. This partial occlusion can lead to excessive PSI upon power injection and lead to catheter failure or emboli of whatever was causing the occlusion. These warnings are for our non valved PowerPICC as well.
I have pasted the Power Injection Warnings from the IFU on our website. I can not speak for other manufacturers products but strongly advocate any power injectable device must be patent, flush easily, and provide an excellent brisk blood return prior to power injection. Primary goal is to prevent patient injury.
I will defer the physics questions to the experts.
Hope this helps.
TimPower Injection Warnings
• Exceeding the maximum flow rate of 5 ml/sec, or the maximum pressure of power injectors of 300 psi, may result in catheter
failure and/or catheter tip displacement.
• Failure to ensure patency of the catheter prior to power injection studies may result in catheter failure.
• Failure to warm contrast media to body temperature prior to power injection may result in catheter failure.
• Use of lumens not marked "Power Injectable" for power injection of contrast media may cause failure of the catheter.
• Power injector machine pressure limiting feature may not prevent over-pressurization of an occluded catheter, which may cause
catheter failure.
• PowerPICC SOLO* catheter indication for power injection of contrast media implies the catheter’s ability to withstand theprocedure, but does not imply appropriateness of the procedure for a particular patient. A suitably trained clinician is
responsible for evaluating the health status of a patient as it pertains to a power injection procedure
Timothy L. Creamer, RN
Clinical Specialist, Bard Access Systems
Florida Division
Timothy L. Creamer RN, CRNI
Clinical Specialist, Bard Access Systems
Florida Division
The information from the sales rep was totally wrong. There is no self-limiting ability for any syringe. The facts are:
1. larger syringes generate less pressure on injection while smaller syringes generate greater pressure on injection.
2. syringe size is only one factor in the whole issue of force, pressure and resistance.
3. the formula is force applied + resistance = increasing intraluminal pressure. The force can be related to syringe size but is also caused by the size and strength of the hand holding that syringe. So it is indeed possible to forceful inject a regular PICC while meeting resistance and damage the catheter.
4. there is no method to use at the bedside for measuring the amount of force being applied and therefore the amount of pressure generated. This leads all catheter manufacturers to make their statements about large size syringes. But no catheter should ever be forcefully injected at any time, especially when meeting resistance.
You were absolutely correct to question what this rep was saying. Always ask for what they are saying in written format as well.
Lynn Hadaway, M.Ed., RN, BC, CRNI
www.hadawayassociates.com
Lynn Hadaway, M.Ed., RN, CRNI
Lynn Hadaway Associates, Inc.
PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861