The purpose of the E-cylinder is to provide backup oxygen in case the pipeline supply fails. They are attached to the anesthesia machine using a hanger yoke assembly and a pin index safety system (PISS). They MUST BE CHECKED prior to administering anesthesia, but always remember to close them after the check (unless you must use them).
A check-valve is located downstream from the E-cylinders – it prevents transfer of gases between cylinders while at the same time allowing cylinders to be changed out without affecting the one in use.
Oxygen cylinders can be pressurized up to 2200 PSIG.
Time Remaining: O2 E Cylinder
- Time remaining (hrs) = Pressure (PSIG) / [200 x flow rate (L/min)]
- Time remaining (hrs) using 0.5 L/min of flow = Pressure (PSIG) / (100)
At a flow rate of 0.5 L/min, a full E-cylinder (2200 PSIG) will provide 22 hours of gas flow.