Longnecker's Anesthesiology > Part 4. Managing Anesthesia Care > Section C. Anesthesia Drugs and Drug Delivery Systems > Chapter 38. Anesthesia Delivery System James B. Eisenkraft, MD

Key Points

"1. A basic understanding of the anesthesia delivery system and its components is important to the provision of safe patient care.

2. The current voluntary consensus standard describing the features of a contemporary anesthesia workstation is the American Society for Testing and Materials (ASTM) F1850–00, published in 2000.

3. A full oxygen tank (E cylinder) has a pressure of approximately 1900 psig (pounds per square inch gauge) and evolves 660 L of gaseous O₂ at atmospheric pressure (14.7 psia [pounds per square inch absolute], 760 mm Hg).

4. By applying Boyle's law, the pressure gauge can indicate fullness of the O₂ tank.

5. Tank O₂ supply is regulated to enter the anesthesia machine at 40–45 psig. Pipeline O₂ is regulated to 50–55 psig.

6. The pin-index and diameter-index safety systems ensure that the correct medical gas enters the correct part of the machine.

7. The "fail-safe" valve (pressure sensor shut-off valve, O₂ failure protection device) only ensures that if the O₂ supply pressure is adequate, nitrous oxide (N₂O) and other gases may flow to their flow-control valves. This valve does not ensure O₂ flow.

8. N₂O can exist as a liquid..."