The objective of the study is to investigate whether or not there will be a significant difference between landmark vs. ultrasound guided approach during Subclavian Central Venous Catheter (SCVC) placement in terms of the success rate, the time it takes to perform the procedure and the complication rate. By using ultrasound to identify anatomical structures that are not seen during the landmark approach, the investigators hypothesize that both the procedural time and the complication rate of ultrasound guided approach should be lower than the landmark approach. The investigators hypothesize that the success rate will be higher in the ultrasound group.