Methods
All CVC procedures were performed for clinical reasons. The decision to perform CVC, either IJVC or FVC, was made by the physician on duty and was not involved in the study. Patients were randomized to the x-plane or single-plane approaches using means of a computer-generated random number table. Vital signs and coagulation indices were recorded.Each cannulation was performed at the patient’s bedside by one of five sonographers with three months of experience in US-guided CVC. They had similar experience with x-plane and single-plane cannulations (> 10 procedures/month; 50% in the x-plane and 50% in the single-plane). Two-lumen 7F, 20 cm-long CVCs (CS-27702, Arrow Gard Blue®; Teleflex Medical IDA, Ireland) were used for infusion and dual-lumen 13.5F, dialysis catheters (5593240/5594150, Niagara ™; Bard Inc., USA) were used for dialysis.