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Desflurane Heated Vaporiser Reason — FRCA Final MCQ

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ModerateAnaesthetic Equipment & SafetyDesflurane Heated Vaporiser ReasonFRCA Final

Desflurane requires a specialised heated, pressurised vaporiser because:

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — It reacts with standard vaporiser metals

Desflurane has a boiling point of 22.8°C – close to or below room temperature in many operating environments. In a standard variable bypass vaporiser, desflurane would boil excessively and unpredictably, producing dangerously high concentrations. The Tec 6 (Datex-Ohmeda) heated vaporiser heats desflurane to 39°C (well above its boiling point) at 2 atm pressure, converting it entirely to vapour. A computer-controlled valve then precisely meters the vapour into the fresh gas flow. This is fundamentally different from the variable bypass principle used for sevoflurane and isoflurane.

Reference: RCOA – 2023 – Anaesthetic equipment: vaporisers; Davis PD – 2019 – Basic Physics