Hey all! Never used a forum before, but I figured this is the best place for my question. I've been a medic for over 10 years in a busy system and have always considered myself very solid. Over the past month or so 80% of my Iv's have been blown due to the catheter not advancing. Good flash every time and I haven't changed my technique. I work in big the ER and fire ambulance setting and have prob done thousands of Iv's with no problems in the past. What is the cause of this I've always considered the valve concept BS. Thanks group