The easiest insertion sites are normally the right internal jugular (RIJ) vein or the left subclavian vein; however, femoral or even brachial vein sites can be used. Prior to starting the procedure, an evaluation of any contraindications to the procedure should be made. In cases with suspected RV dysfunction, pulmonary artery hypertension, tricuspid regurgitation, or RA enlargement, consideration should be given to placing the PAC with fluoroscopic guidance, as direct visualization enhances ability to pass the PAC in difficult cases.

The intravenous lines, pressure bags, transducers, and zeroing apparatus should all be assembled and ready prior to the sterile insertion of the PAC. It is useful to have an assistant or nurse available for the procedure. A sterile procedural field should be used, with strict attention to handwashing, mask and cap usage, sterile glove and gown use, as well as full-length drapes. The introducer catheter is inserted in a similar manner to a central venous catheter using the Seldinger technique. The introducer catheter is slightly different in that the dilator is advanced through the introducer rather than as a separate piece of equipment, as occurs with a regular central venous catheter insertion. Additionally, the guidewire and dilator are removed together at the conclusion of the introducer insertion, which leaves the introducer alone in the vessel.

The PAC (Fig. 80.1) should have all ports flushed and the balloon checked for leaks prior to insertion. In addition, the operator should check that the balloon tip does not protrude beyond the inflated balloon as this can increase the risk of vascular rupture. All ports of the PAC should be attached to the pressure transducers and flushed prior to insertion. Waving of the catheter tip prior to insertion with verification of a waveform on the monitor confirms that the catheter ports are correctly attached. Prior to starting the procedure, a final check to verify that the protective catheter sheath has been inserted over the catheter should be performed. The catheter should be oriented prior to insertion to match the natural curve in the catheter to the projected course through the vasculature.

The PAC is advanced through the introducer, and when the catheter tip is in the RA, the balloon should be inflated gently. The distance from the insertion site to the RA will vary depending on site, but is usually 15 to 20 cm from the RIJ or left subclavian sites. Once the balloon is inflated and the lock on the inflating syringe has been activated, the catheter is advanced and the waveforms on the monitor are inspected. The RA waveform will increase in amplitude as the RV is entered, which normally occurs at approximately 30 cm (from a RIJ approach). The passage of the catheter through the RV is arrhythmogenic and should not be of prolonged duration. Conversion of the RV waveform to a PA waveform, as the catheter tip traverses the pulmonary valve, is identified by an increase in the diastolic pressure and the development of a dicrotic notch in the tracing (often at 40 cm). Difficulty in traversing the pulmonary valve is not uncommon in patients with pulmonary arterial hypertension from any cause and, if excessive catheter length has been advanced without this transition occurring, the most likely explanation is that the catheter is coiled in the enlarged RV. If this occurs, the balloon should be deflated and the catheter should be withdrawn until an RA tracing is obtained, after which the balloon should be inflated and the procedure attempted again. The pulmonary capillary wedge pressure tracing is identified by loss of the arterial tracing to a flatter tracing of lower amplitude than the PA diastolic pressure (often at 50 cm) (Fig. 80.2 for the pressure tracings obtained as the catheter advances).