Review Notes DETAILS
WHAT IS BOWIE DICK TEST?
Bowie Dick Test is a diagnostic visual test performed to ensure the dynamic-air-removal system (Vacuum system) of a steam sterilizer is effective in removing any air that may be trapped or leaked into the sterilization chamber. The test must be done before the pre-vacuum cycle and after the conditioning phase
CS technician must not use the sterilizer for prevacuum cycle if the unit does not pass the Bowie-Dick test.
Air trapped in the sterilizer chamber, affects the ability of steam to penetrate the load (wrapped instruments)
Bowie Dick consists of pack of special sheet of paper. The color change pattern of the sheet is used to determine the test result.
If at the end of the cycle, there was a UNIFORM color change of the test sheet, the test is considered NEGATIVE or passed. A successful Bowie-Dick Test means, load sterilization can begin with a pre-vacuum cycle
If at the end of the sterilization cycle, the color change was non-uniform or was patchy, the test is considered POSITIVE or failed. It means air is entrapped in the chamber
If the test is POSITIVE, it indicates that the air removal system of the sterilizer cannot be relied upon. If the test failed (POSITIVE), the sterilizer CANNOT be used.
The sterilizer must be taken out of order and the incident reported to the biomedical engineering department to troubleshoot and fix the problem
Bowie-Dick testing should be performed on dynamic-air-removal sterilizers on the pre-vacuum cycle
Running Bowie-Dick test requires placing a disposable test pack into the empty chamber and running a 3 1/2 to 4 minutes sterilization cycle at a temperature of 270 – 273 degrees F
WHERE TO PLACE BOWIE DICK TEST PACK
Bowie-Dick test packs should be placed in an empty chamber directly above the drain on the bottom rack
Note that the test should not be placed with any load in the chamber. The chamber must be completely empty except for the Bowie Dick test apparatus
WHAT CHEMICAL CLASS DOES BOWIE DICK TEST BELONG TO?
The Bowie-Dick Test is a Class 2 Chemical Indicator
WHEN TO PERFORM BOWIE DICK TEST
- The test should be performed each day the sterilizer is used
- Bowie Dick test should ALWAYS be performed before the first processed load.
- In department where the sterilizer is used continuously, the Bowie Dick test should be performed AT THE SAME TIME, EACH DAY
- Bowie-Dick testing should be performed after the sterilizer is shut down and restarted
- Bowie-Dick should be performed after a major repair
CAUSES OF BOWIE DICK TEST FAILURE
- Poor air removal
- Poor steam quality
- Super heat conditions.
- Leaks in the piping
BOWIE DICK TEST PACK
Dynamic air removal leak test or Vacuum leak test is used to determine whether the prevacuum autoclave chamber and plumbing system is air-tight.
It is used to verify the air-tight integrity of a prevacuum autoclave chamber and plumbing system.
In addition to Bowie-Dick Test, leak test should be done at least weekly in an empty chamber to ensure the prevacuum steam sterilizer is air tight.
Since leak test is more sensitive in air detection, it is performed when the prevacuum autoclave fails Bowie-Dick test
To effectively ascertain the absence of leaks in the sterilizer plumbing or seal, daily Bowie-Dick test is combined with weekly leak test. The two complement each other.