After introduction via the RIJ or the right/left subclavian vein, the right atrium should be reached at approximately 20 cm insertion depth; the right ventricle at 30–35 cm, the pulmonary artery at 40–45 cm, and the wedge position at 50 cm
For the left IJ insertion, one should add 5 cm to each of the previously mentioned landmarks.
Zeroing
Opening the stopcock to ambient air, the hemodynamic monitoring system will be exposed to atmospheric pressure.
After pressing ‘zeroing’ on the monitor and confirming the calibration, the transducer stopcock can be turned back into its original position. The atmospheric pressure is now the zero-reference point. From there on, only (variations in) pressures which exist inside the heart chamber or blood vessel will be measured, as long as the position of the pressure transducer remains the same.
Waveforms
CVP
A normal CVP waveform consists of 5 phases; three peaks (a-wave: atrial contraction; c-wave: isovolumic ventricular contraction, tricuspid motion toward right atrium; v-wave: systolic filling of the atrium), and two troughs (x: atrial relaxation; y: early ventricular filling).
