Abstract
Bowie-Dick test is used to detect inefficient vacuum pump function, inward air leak into the chamber and non-condensable gases in the supplied steam. Health Technical Memorandum 2010 recommends to perform vacuum leak test when prevacuum autoclave fails to pass Bowie-Dick test, because the state of vacuum pump function and the degree of inward air leak into the chamber are evaluated, respectively, using this test. However, the microprocessor-controlled prevacuum autoclave installed in our surgical center is not equipped with the automatic vacuum leak test mode. The authors devised a simple method to perform vacuum leak test in our prevacuum autoclave: the microprocessor boards were operated manually when the test was performed. In the present study, vacuum leak test was performed twice in the prevacuum autoclave when it failed to pass Bowie-Dick test: before and after it underwent the mechanical repair. Vacuum leak test detected the impaired function of the vacuum pump, which had been replaced four years previously. After this impaired vacuum pump was replaced with a new one, the prevacuum autoclave passed Bowie-Dick test. Moreover, this impaired vacuum pump was disassembled to clarify the cause of its impaired function. The main parts underwent rusty corrosion. The present study suggested that vacuum leak test is performed easily using our method in the prevacuum autoclave without the automatic test mode. It is also suggested that vacuum leak test is useful in the repair of the prevacuum autoclave failing Bowie-Dick test.
