Anaes Vivas · The anaesthetic machine

Equipment viva — the anaesthetic machine and its safety devices

The classic equipment viva on the anaesthetic machine — the four-stage pressure path from the pipeline and cylinder supply to the common gas outlet, with the cylinder regulator, the Thorpe-tube flowmeters, the Link-25 hypoxic guard, the O2-last arrangement, the oxygen supply failure device with its weekly alarm test, the emergency oxygen bypass, and the oxygen analyser as the final defence. The discriminating details are the exact pressures (pipeline gauges 400 to 500 kPa, O2 cylinder 137 bar, N2O above 5000 kPa with liquid present), the distinction between the fail-safe and the analyser, and the closed-claims toll of gas-delivery error.