Q: If I don’t get a blood return when checking a PIV for patency before administering an IV, does that make it unsafe to proceed?

A: While verification of a blood return on a short peripheral IV is the common way to check for patency, sometimes, it is difficult to obtain a blood return in dwelling PIVs, particularly in small gauge catheters such as a 22g or a 24g. In addition, fibrin may also begin to form and build up on the tip of the catheter contributing to the inability to obtain blood return.

Having said that, the presence of a blood return does not always provide absolute verification of placement/patency. If the tip of the PIV catheter punctures the posterior wall of the vein with the majority of the catheter tip still in the vein, a blood return may be obtained and at the same time, the fluid infusing could be infiltrating into the tissue.

It is always best not only to assess for blood return, but also for redness, tenderness, swelling, drainage, and/or the presence of paresthesia, numbness, or tingling by visualization and palpation of the PIV site as well as subjective information from the patient.

Is it unsafe to proceed? Your question did not mention what kind of IV solution you will be administering via the PIV. The Infusion Nurses Society Standards of Practice states

“therapies not appropriate for short peripheral catheters, include continuous vesicant therapy, parenteral nutrition, infusates with pH less than 5 or greater than 9, and infusates with an osmolality greater than 600mOsmol/L.”

For more information, look up the references I always use:

1. Infusion Nurses Society. Infusion nursing standards of practice. J Infus Nurs. 2011;34(1S). click here.

2. INS Position Paper: Recommendations for Frequency of Assessment of the Short Peripheral Catheter Site.  Click here