A size E compressed-gas cylinder completely filled with nitrous oxide contains approximately how many liters?

A size E compressed-gas cylinder completely filled with nitrous oxide contains approximately how many liters?

• A. 1160 L
• B. 1470 L
• C. 1590 L
• D. 1640 L

Answer: (C)

Nitrous oxide in an E cylinder is a liquefied gas, stored with as a liquid that constantly vaporizes to gas as it’s drawn off. Because of this liquid–gas equilibrium, a full cylinder contains a large volume of gas at standard conditions even though the pressure isn’t extremely high. For an E-sized cylinder, this usable gas content is about 1590 liters. That’s why the best answer is the one around 1590 liters—the figure clinicians memorize for N2O in an E cylinder. The other numbers don’t reflect the typical standard-liter content for this gas and cylinder size. This concept helps you estimate how long a cylinder will supply gas at a given flow rate during anesthesia.

Nitrous oxide in an E cylinder is a liquefied gas, stored with as a liquid that constantly vaporizes to gas as it’s drawn off. Because of this liquid–gas equilibrium, a full cylinder contains a large volume of gas at standard conditions even though the pressure isn’t extremely high. For an E-sized cylinder, this usable gas content is about 1590 liters.

That’s why the best answer is the one around 1590 liters—the figure clinicians memorize for N2O in an E cylinder. The other numbers don’t reflect the typical standard-liter content for this gas and cylinder size. This concept helps you estimate how long a cylinder will supply gas at a given flow rate during anesthesia.