You should always change out O2 cylinders before they fall below which pressure?

• A. 500 psi
• B. 100 psi
• C. 1000 psi
• D. 200 psi

Answer: (D)

Oxygen cylinder management is about keeping a safety margin so you can deliver oxygen without interruptions. Switching cylinders when the gauge reads about 200 psi gives you enough of a buffer to complete the swap, reconnect and resume delivery even if there’s a delay or higher patient demand. Waiting until the pressure is much lower risks running out in the middle of care, while waiting until very high pressures would cause unnecessary changes. The 200 psi mark provides a practical balance between staying ahead of depletion and not changing cylinders too often.