This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Inhalational Anesthetic Agents, Subject name: Anaesthesia
Tec 6 vaporizer is used with......... 
Select and explain. 
A. Halothane, B. Desflurane, C. Isoflurane, D. Trielene
B: Desflurane
Answer: B: Desflurane 
Explanation: The most common such vaporizer is the Ohmeda Tec 6, designed specifically for use with desflurane. Desflurane has two physical propeies, making it unsuitable for use with a conventional vaporizer. First, it has a very high SVP (88.5 kPa at 20degC). A conventional vaporizer would require high fresh gas flows to dilute it to within clinically useful concentrations, making it uneconomical. Secondly, it has a low boiling point (23.5degC). At room temperature, it will intermittently boil resulting in large fluctuations in agent delivery. When boiling, there will be excessive agent delivery; however, it will then cool due to a large loss of latent heat of vaporization, resulting in an exponential decrease in SVP and under-delivery of agent. The Ohmeda Tec 6 overcomes these problems by using an electrical filament that heats the desflurane to 39degC, raising its SVP to 194 kPa, that is, nearly 2 atm. In addition to providing a stable SVP, this high pressure removes the need for a pressurized carrier gas--instead, the fresh or diluent gas is entirely separate from the vaporizing chamber