Question 28.1
1. With regards to the device pictured below:
a) Identify the lumens / lines labelled A, B, C, D, E
b) List the parameters that can be directly measured using this device.
College Answer
a) Identify the lumens / lines labelled A, B, C, D, E
A right atrial lumen
B thermistor
C mixed venous oximeter
D pulmonary artery lumen
E balloon inflation/deflation
b) List the parameters that can be directly measured using this device.
• Right atrial pressure
• Right ventricular systolic and diastolic pressure
• Pulmonary artery systolic and diastolic pressure
• Pulmonary artery occlusion pressure
• Mixed venous saturations
• Core temperature
Discussion
Here is a diagram of the important ports:
The following "direct" measurements can be made:
- Core temperature
- RA pressure
- PA pressure
- PA wedge pressure
- Mixed venous saturation
With a malpositioned catheter, one could potentially also read the RV pressure, the IVC pressure and the hepatic venous pressure. Anatomy of the PA catheter is discussed elsewhere, as are the directly measured and derived variables.
References
This a full-text version of the seminal paper from 1970:
Swan HJ, Ganz W, Forrester J, Marcus H, Diamond G, Chonette D (August 1970). "Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter". N. Engl. J. Med. 283 (9): 447–51.
A manufacturer (Edwards) offers some free information about the PA catheter on their product page.
The PA catheter section from The ICU Book by Paul L Marino (3rd edition, 2007) is a valuable read.