<prompt> 46 yr old chronic smoker came to emergency dept with a history of difficulty in breathing fever since 1day, postgraduate tells you to connect face mask to which pin index number1, 52, 53, 51, 6  <response>: - Machines are usually equipped with one or two E type cylinders that hang on specific hanger yokes. - The medical gas pin-index safety system ensures that the correct medical gas cylinder is hung in the correct yoke. Gas Index Pins Oxygen 2,5 Nitrous oxide 3,5 Cyclopropane 3,6 O2-CO2 CO27.5 2,6 O2-CO2CO27.5 1,6 O2-heHe80.5 4,6 O2-heHe80.5 2,4 Air 1,5 Nitrogen 1,4 N2O-O 7 