Two approaches such as ultrasound (US)-guided and prelocation techniques are possible when
the internal jugular vein cannulation is attempted with US. This study is a clinical trial
that compares the success rates of both techniques and shows the non-inferiority of the
prelocation technique. However, during prelocation technique, rotated screen of the US is
used instead of original screen. The angle of rotation is determined by the degree of
rotation of US probe where an accelerometer is attached.