The electrode used to measure PCO2 in transcutaneous monitoring is named for Severing and which other scientist?

• A. Severing-hause
• B. Severing-Katz
• C. Severing-Pouteau
• D. Severing-Relief

Answer: (A)

The main idea here is recognizing the CO2 sensor used in transcutaneous monitoring, which is the Severinghaus electrode. This electrode technology converts CO2 that diffuses through a gas-permeable membrane into a change in pH within a buffered solution, and that pH change is then read by a pH sensor to derive the PCO2. The device is named after Severinghaus, who pioneered this approach, and in historical references you’ll also see Katz cited as a collaborator in the development of the CO2 electrode. That’s why the Severinghaus name is the defining part you’d look for when identifying this electrode, with Katz often mentioned alongside him in older literature.