Pistoning is a term used in the vascular access specialty to describe the small, repeated movement of a peripheral vascular access device (PVAD) or central venous access device (CVAD) in and out at the insertion site. Movement may occur for several reasons including the placement of the vascular access device (VAD) in an area of flexion, inadequate securement during activities of daily living, or absence of securement during dressing changes.
Most vascular access specialists can describe pistoning, but can struggle to know what amount of pistoning is acceptable. How many millimeters (mm) are there in the retraction and advancement of a catheter that would be defined as “pistoning”? 1,2,3 mm? At what measurement is the retraction enough to be considered an external portion of the catheter? Is there a specific amount of time that the external portion must be on the skin before it should “never be advanced” back into the body?
Here is the Infusion Nurses Society’s (2021) statement on CVAD dislodgement:
Never advance any external portion of the CVAD that has been in contact with skin into the insertion site. No antiseptic agent or technique applied to skin, or the external catheter will render skin or the catheter to be sterile, and no studies have established an acceptable length of time after insertion for such catheter manipulation.1
Considering this instruction in the INS Standards, one can conclude that the amount of catheter retracted out of the insertion site is irrelevant to the statement “never advance any external portion”. Understanding that humans move and that there is no suitable tool to measure catheter movement in micrometers (0.001 mm) I suggest the following definition of VAD pistoning:
Pistoning is any visible movement of a vascular access device retracting and advancing repeatedly at the insertion site, with or without a securement device or dressing in place. (Hawes, 2023)
With the understanding of the INS statement and this definition of pistoning please watch this brief video clip of a typical CVAD cleaning when the engineered securement device has been removed. Notice the pistoning that takes place in this common care practice.
In an article by Barton, et.al., 2022, the authors describe the migration of cutaneous microflora as the most important causative factor for Catheter Related Blood Stream Infections (CRBSI).2 Migration of microflora is indifferent to the length of the catheter that was placed and is also a factor in Hospital Acquired Infections (HAI) related to PVADs including short peripheral intravenous (PIV) catheters and peripheral midlines.3
When inserting any VAD it is best to avoid areas of flexion.1 This is an important consideration for the patient’s comfort and the stabilization of the device to minimize movement of the catheter. Catheter movement can also be caused by inadequate securement immediately after insertion and over the week between dressing changes. Patients are encouraged to be mobile and as active as possible regardless of their VAD. Many people live with a CVAD for weeks, months, and years. The activities of daily living require attention to dressing and securement integrity to minimize catheter movement.
One of the truly precarious events in living with a VAD is the weekly dressing change. There are a variety of transparent dressings but there are only 4 categories of engineered securement devices (ESDs) see the table below.1
The adhesive securement device (ASD) and integrated securement device (ISD) are removed with each dressing change as shown in the video leaving the catheter free to piston, migrate, or dislodge completely. Tissue adhesive (TA) will degrade, or slough, over a week and should be reapplied at each dressing change causing the catheter to be manipulated without securement during that time.
Only the SASS remains with the catheter from insertion to removal. The SASS is not removed during dressing changes which will secure the VAD throughout 360-degree cleaning of the catheter insertion site and surrounding area. Watch this video of a dressing change with a SecurAcath (SASS) in place and compare it with the one above. Which securement device better addresses pistoning?
The external portion of a VAD should never be advanced into the insertion site.1 No specific length of catheter or time it must be in contact with the skin has been defined. Skin cannot be sterilized regardless of the antiseptic solution, therefore if you can visualize any portion of the catheter moving in and out of the insertion site there is a high degree of certainty that skin flora is being dragged into the body.2
Eliminating the risks caused by pistoning begins with an optimal VAD placement out of the areas of flexion. Movement is further controlled by using a properly placed ESD and dressing. Pistoning is eliminated during activities of daily living and dressing changes by using a SecurAcath for the life of the line.
- Gorski LA, Hadaway L, Hagle ME, Broadhurst D, Clare S, Kleidon T, et al. Infusion Therapy Standards of Practice, 8th Edition. J Infus Nurs. 2021 Jan;44(1S):S1–224.
- Barton A, Bitmead J, Clare S, et al. How to improve aseptic technique to reduce bloodstream infection during vascular access procedures. British J Nurs. 2022;31(17): 880-885. doi:10.12968/bjon.2022.31.17.880
- DeVries M, Lee J, Hoffman L. Infection free midline catheter implementation at a community hospital (2 years). Am J Infect Control [Internet]. 2019;47(9):1118–21. doi.org/10.1016/j.ajic.2019.03.001