In school I've been taught both techniques of placing radial a-lines. Some place them directly into the artery, flash, then advance. Others go "through-and-through" the artery, flash, and then back it into the lumen. I have my preference for which technique and my reasons for them but I'm wondering which techniques others use, which they prefer and why. Are there times when you will use the direct method and other times will use through-and-through? What dictates which method you will use? Just curious.