. The median number of previous ultrasound-guided internal jugular catheters was 25 (interquartile range, 9-40), and ultrasound-guided subclavian catheters were three (interquartile range, 0-5). The long-axis view was associated with a significant decrease in the number of redirections at the internal jugular and subclavian sites, relative risk 0.4 (95% CI, 0.2-0.9) and relative risk 0.5 (95% CI, 0.3-0.7), respectively