Analysis of sterilization failure of autoclave

Autoclaves are indispensable equipment in microbial experiments and hospital disinfection and sterilization. Don’t panic when sterilization failure occurs.
I. Improper loading
Improper loading causes steam penetration obstacles. Sterilized items should not be placed too tightly or too full. When placing them, pay attention to staggered stacking up and down to leave gaps, which facilitates steam circulation.
Improvement measures:
Sterilize items of the same type in the same autoclave. When sterilizing items of different types in the same autoclave, place dressing packs on the upper layer and metal packs on the lower layer;
Place items that are prone to producing water droplets on the lower layer as much as possible;
Use dedicated sterilization baskets for loading, do not stack items, and keep a gap of at least 2 centimeters between packs;
Surgical instrument trays should be placed flat, fabric packs should be placed vertically, and surgical basins should be placed obliquely;
Items packaged with paper-plastic materials should be placed vertically in baskets or on racks.
II. Selection of inappropriate sterilization parameters
The sterilization method is incorrectly chosen. Especially for sterilization objects with complex structures, as well as for external medical devices, implants, rigid containers, and oversized/overweight packs, the sterilization parameters provided by the manufacturer should be followed.
Improvement measures:
Follow the manufacturer’s instruction manual — Sterilize according to the manufacturer’s sterilization parameters;
For the first sterilization of external medical devices — Test the sterilization parameters;
Inspect the sterilizer annually — Test the sterilization parameters;
When sterilizing some hard-to-sterilize microorganisms, it is necessary to appropriately extend the sterilization time. For example, when sterilizing the pathogen of mad cow disease (bovine spongiform encephalopathy) and prions, the sterilization time needs to be extended.
III. Improper preprocessing of sterilized items
Ineffective cleaning, which affects the penetration of the sterilizing medium;
Insufficient disassembly of metal instruments;
Packaging materials that do not allow steam penetration;
Sterilization packages that are oversized, overweight, or excessively dense;
Improvement measures:
Conduct effective cleaning according to the requirements of the sterilized items, and follow the manufacturer’s instruction manual or guidebook;
Disassemble metal instruments as required;
For sealed packaging materials, materials such as paper bags and paper-plastic bags should be selected;
The weight of instrument packs should not exceed 7KG, and the weight of dressing packs should not exceed 5KG;
IV. Wet packs
Wet packs themselves are sterile, but when water comes into contact with permeable packaging materials, a microbial migration channel can form due to the principle of siphonage. This provides conditions for external microorganisms to enter, potentially leading to contamination of the sterilized items.
Improvement measures:
Strengthen staff training;
Ensure the sterilizer is prepared before sterilization and comply with reasonable loading requirements;
Package various items separately;
Dry the sterilized items;
V. Inadequate discharge of cold air
The temperature of steam in a pressure steam sterilizer is related not only to pressure but also to the saturation of the steam. If the cold air in the sterilizer is not completely discharged, saturated steam cannot be achieved, and this will affect the penetration ability of high-pressure steam.
Improvement Measures:
Set the altitude;
When sterilizing waste, put about 300-500ml of water into the sterilization bag to avoid air residue inside the bag;
When sterilizing a large quantity of items, appropriately extend the cold air discharge time;
When sterilizing sealed containers with lids, the lids should also be opened or loosened before sterilization;
Zealway Autoclave adopts an intelligent control system with powerful functions. It realizes fully automatic control of the sterilization process, can automatically monitor the discharge of cold air, ensures a pure steam sterilization environment, and guarantees optimal sterilization effects.
The essence of sterilization is to achieve a sterile state. The success of sterilization requires strict control over multiple aspects including equipment, personnel, packaging, and operational details to ensure sterilization quality.