Features
The basic features of a PA catheter are shown in Figure 8.1. The catheter
is 110 cm long and has an outside diameter of 2.3 mm (about 7 French).
There are two internal channels: one channel emerges at the tip of the
catheter (the distal or PA lumen), and the other channel emerges 30 cm
proximal to the catheter tip, which should be situated in the right atrium
(the proximal or RA lumen). The tip of the catheter has a small inflatable
balloon (1.5 mL capacity) that helps to carry the catheter to its final des-
tination (as just described). When the balloon is fully inflated, it creates a
recess for the tip of the catheter that prevents the tip from damaging the
vessel wall as the catheter is advanced. A small thermistor (a tempera-
ture-sensing transducer) is placed near the tip of the catheter. This device
is involved in the measurement of cardiac output, as described later in
the chapter.
Placement
The PA catheter is inserted through a large-bore (8–9 French) introducer
sheath that has been placed in the subclavian vein or internal jugular
vein (see Figure 8.1). The distal lumen of the catheter is attached to a
136
Hemodynamic Monitoring
Introducer Catheter
RA Lumen
PA Lumen
Inflated
Balloon
Thermistor
FIGURE 8.1
The basic features of a pulmonary artery (PA) catheter. Note that the PA
catheter has been threaded through a large-bore introducer catheter that has a side-arm
infusion port.
