CHECKING ANESTHESIA MACHINES

A complete anesthesia apparatus checkout procedure should be performed each day before the first case. An abbreviated version should be performed before each subsequent case. Several checkout procedures exist, but the 1993 Food and Drug Administration (FDA) Anesthesia Apparatus Checkout Recommendations reproduced in Appendix 1 is the most popular. ^{[159] [160] [161] [162] [163]} The FDA checkout procedures serve only as generic guidelines because the designs of different machines vary considerably. Many machines have been modified in the field. Specific checks must be performed on specific machines. The user must refer to the operator's manual for special procedures and precautions.

The three most important preoperative checks are calibration of the oxygen analyzer, a leak test for the low-pressure circuit, and a test of the circle system. They are discussed in subsequent sections.

Calibration of the Oxygen Analyzer

The oxygen analyzer is the most important machine monitor because it is the only machine safety device that evaluates the integrity of the low-pressure circuit. Other machine safety devices, such as the fail-safe valve, the oxygen supply failure alarm, and the proportioning system, are all upstream from the flow control valves (see Fig. 9-3 ). The only machine monitor that detects problems downstream from the flow control valves is the oxygen analyzer. Calibration of this monitor is described in step 9 of Appendix 1 .