Teaching central line placement: no clear window

We appreciate Maizel and colleagues addressing the teaching of ultrasound-guided central line placement to medical residents [1]; however, we have several comments. We feel that the success rates reported in this study are artificially high since most residents in 2014 are training with the use of ultrasound, and it is highly unlikely that the initial procedures being done by these senior residents (fourth and fifth year medical residents) were their first experience. In addition, by teaching the landmark technique second, the residents at that time are definitely experienced with the procedure of central line placement. The shorter procedure time noted for the landmark technique is likely related to the fact the practitioners are