The anesthesia machine valve tester: a new device and method for evaluating the competence of unidirectional anesthetic valves.

OBJECTIVE: Current methods of determining anesthesia machine unidirectional valve (UDV) competence are time-consuming, ineffective, or carry the risk of transmitting infectious disease to the anesthetist or patient. New methods of testing these valves are needed. The purpose of this study was to determine the prevalence of incompetent UDVs at one institution by employing the Anesthesia Machine Valve Tester (AMVT), a new way to test anesthesia machine UDVs.
METHODS: We tested each expiratory and inspiratory UDV on all anesthesia machines in functioning operating rooms at the Brigham and Women's Hospital. If a UDV was found to be incompetent, we cleaned and reseated it, and then tested it again with the AMVT.
RESULTS: We found a 13% prevalence of UDV malfunction in our machines. Three of the 10 incompetent valves were repaired quickly by us and were made competent by either reseating the valve or by first cleaning and then reseating it.
CONCLUSIONS: We found that the AMVT was able to detect UDV failure quickly with no risk to the tester or to the patient. We conclude that the AMVT can be used to check the UDV as recommended by the FDA anesthesia machine check-out protocol.