Wet packs are defined as moisture in or on a tray following an approved completed sterilization cycle. Wet packs must be avoided because moisture can serve as a growth media or provide a means for organisms to travel back into a sterile pack. If wet packs are discovered, the load must be reprocessed.
Wet packs are unfortunately a periodic, albeit highly emotional, frustrating, and costly issue for many users of steam sterilizers, regardless of brand.
When analyzing the root cause(s) of wet packs, it is best to remember that wet packs are not simply random events, but are often complex problems with several variables that have their origin in the laws of physics and thermodynamics.
Steam Quality
Some things that can cause poor steam quality include:
- Malfunctioning steam traps
- Poor steam pipe insulation
- Time of the year
- Time of the day
- Additional loads
- Steam supply lines
- Boiler condition
Four Major Cause Areas
- Steam quality to the sterilizer
- Pack/Material preparation and loading density
- Operation and maintenance of the sterilizer
- Pack/Material handling after the sterilization process
Adding to this complexity is the fact that wet pack problems are often intermittent. Also, several different parties often play a role in discovering and solving the problem(s) – central sterilization technicians. Facility maintenance, ASAs, the sterilizer manufacturer, surgery, etc. As most of you have likely experienced with wet pack complaints, emotions can sometimes play a larger role than logic and must be considered when dealing with these issues.
Basic Initial Troubleshooting Questions and Data Collection
When first approached about a wet pack issue, you should observe directly or ask the following questions and record the data for further evaluation and troubleshooting:
- Date and time wet packs were first noted?
- Are the sterilizer cycle parameters set correctly?
- Who operated the equipment during the cycle where wet packs were found?
- Do one or more employees experience wet packs more than other employees?
- How long has the employee been operating the sterilizer? Is he/she inexperienced? New?
- Do wet packs generally occur at a certain time each day?
- Do they happen only on certain shifts?
- Do they occur more frequently in a particular season of the year?
- What is the humidity in the area where the packs were assembled and wrapped?
- What maintenance has recently been conducted on the sterilizer?
- What maintenance has been conducted recently on the boiler and associated systems?
- Do wet packs occur only with certain size/type of instrument trays or containers?
- How densely packed are the sterilizer loads? Is there adequate space for steam circulation or could dead zones form in chamber?
- Are only approved trays and loading carts (if applicable) being used?
