This came up in Question 28.1 from the first paper of 2011. The anatomy of the pulmonary artery catheter is discussed in greater detail elsewhere. This is a brief summary, of which the most important aspect is really this diagram:
When handling one of these things in a viva, one may be expected to mention some of the safety features.
Safety features of the PA catheter include the following:
- The syringe plunger is limited to a maximum volume of 1.5ml
- The syringe port can be locked in the closed position, preventing accidental wedging
- The transparent sliding lock device allows the catheter depth to be manipulated without increased risk of infection
- 10cm interval markings on the catheter allow depth of insertion to be reliably documented
- The catheter is made of PVC, which softens at body temperature, reducing the risk of injury to intracardiac structures
- Lumens have standard colours across manufacturers, to prevent confusion:
- Red = balloon
- Yellow = distal PA
- White = RA (31cm)
- Blue = RA (30cm)
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.
Armstrong, Ehrin J., James M. McCabe, and Melvin D. Cheitlin. "Pulmonary artery catheterization in the intensive care unit: just numbers floating by?."Archives of internal medicine 171.12 (2011): 1110-1111.
Additionally, UpToDate has an article on PA catheter complication