Do you notice the patient's reaction to vein entry?

[Gwen Irwin]

This may seem to be a weird topic, but with our years of ultrasound insertion of PICCs, we have noticed that some patients really react to vein entry BEFORE we are close to entering the vein, while observing on ultrasound the location of the needle in relation to the vein wall.  When we proceed past that point, we are in the vein with excellent blood return and proceed to successful PICC insertion.  Local anesthesia works only on the skin entry and doesn't prevent this reaction to vein entry.  They also react differently to vein entry of the dilator/sheath introducer.   This population of patients are also the ones that complain of the most pain with IV insertions.  Most staff nurses give up before entering the vein with an IV catheter, when the patient complains of this pain.  If we are called to do a PIV, we don't give up at that point, but believe that we are right on top of the vein and continue past the patient's complaint to vein entry.  We have a successful PIV.   This is so hard to measure for a study, but our observations have led us to believe that the innervation of the exterior of the vein is different for some people.  We don't seem to see a large percentage of our patients that have this type of reaction, but it is noticeable, when it occurs.  Some of these people call themselves "weenies" for IV starts.  Based on the years of our observations, we don't believe that they are weenies, but that they have different innervation that actually gives them a pain signal before vein entry.  We have been known to tell them that they have bad luck with their veins, since they feel the stick into the vein before it actually occurs.  These also can be the patients that have more vasoconstriction observed on ultrasound, during PICC attempts.  We have waited for as long as 10 minutes to observe the vein stop its vasospasm, and see the dilation that we initially saw on our original assessment.   I am wondering if anyone else is noticing this phenomenon.  I am really thinking it would be useful information to share, but don't know how to study or report this subjective observation.   I would love to hear from you, if you think we are crazy or if we are noticing something that has not previously reported or discussed.  We have seen it so many times that we don't think we are crazy.  Your responses are always appreciated.   Gwen Irwin Austin, Texas