Circle rebreathing — FRCA Primary MCQ

Correct answer: A — Circle system exhausted absorbent

Exhausted absorbent or valve failure causes CO2 rebreathing. Non-interchangeable screw thread is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Heat and moisture exchanger is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Hypoxic guard is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Leakage current control and isolation is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. In Primary FRCA physics and measurement, the safest answer is the one that follows the underlying physical principle and the limitations of the device.

Reference: Davis and Kenny Basic Physics and Measurement in Anaesthesia; RCoA Primary FRCA syllabus