Gas from an N2O compressed-gas cylinder enters the anesthesia machine through a pressure regulator that reduces the pressure to which value?

Gas from an N2O compressed-gas cylinder enters the anesthesia machine through a pressure regulator that reduces the pressure to which value?

• A. 60 psi
• B. 45 psi
• C. 30 psi
• D. 15 psi

Answer: (B)

Gas stored in compressed cylinders is at very high pressure, so a regulator is used to bring that pressure down to a usable, stable level for the anesthesia machine. For nitrous oxide, the regulator is designed to output about 45 psi. This provides a predictable downstream pressure that the flowmeters and related components are calibrated for, allowing accurate and consistent gas delivery as you set the flow rates. If the pressure were much higher or lower, the measured flow at the flowmeters would be inaccurate, potentially delivering too little or too much gas. The regulator maintains this downstream pressure even as cylinder pressure falls, until the cylinder becomes nearly empty.

Gas stored in compressed cylinders is at very high pressure, so a regulator is used to bring that pressure down to a usable, stable level for the anesthesia machine. For nitrous oxide, the regulator is designed to output about 45 psi. This provides a predictable downstream pressure that the flowmeters and related components are calibrated for, allowing accurate and consistent gas delivery as you set the flow rates. If the pressure were much higher or lower, the measured flow at the flowmeters would be inaccurate, potentially delivering too little or too much gas. The regulator maintains this downstream pressure even as cylinder pressure falls, until the cylinder becomes nearly empty.