I've been doing US IV's for the past month and have only missed once or twice due to patient movement; however, today was a different story. I was inserting a 20g IV into a 0.30cm cephalic vein that was 1.0cm deep. I visualized the catheter in the vessel but could not get blood return or flash back. I looked at it longitudinally and could see that my catheter was in the vessel. I sat there and looked at it, tracked it up and down and looked at it every which way but could not see any reason why I was unable to get any blood return or flash.
can anyone explain this to me?