Regarding the Tec 6 vaporizer used for desflurane, which combination of operating conditions is correct?

• A Unheated but pressurised to approximately 2000 mmHg
• B Heated to 25 degrees Celsius and pressurised to approximately 760 mmHg
• C Heated to 50 degrees Celsius and pressurised to approximately 300 mmHg
• D Heated to 39 degrees Celsius and pressurised to approximately 1500 mmHg ✓

Explanation

Desflurane boils at 22.8 degrees Celsius, close to room temperature, making output from a variable bypass vaporizer unpredictable. The Tec 6 heats the agent to 39 degrees Celsius and pressurises the sump to about 1500 mmHg (roughly two atmospheres), creating a constant saturated vapour state. The dial then meters pure desflurane vapour into the fresh gas stream, and output is independent of altitude, fresh gas flow rate, and back pressure. Conventional plenum vaporizers cannot achieve this control.

Reference: Miller's Anesthesia, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.