Drugdu.com expert's response:

The sterilization of medical endoscopes requires the selection of appropriate methods based on their material, structure, and usage scenarios. Common sterilization methods and their operational key points are as follows:

I. Selection of Sterilization Methods

1.Sterilization of Heat and Pressure-Resistant Instruments

Applicable Objects: Rigid endoscopes made of stainless steel (e.g., laparoscopes, arthroscopes) and detachable metal components.

Sterilization Method: Pressure steam sterilization (at 132°C and 2.1 bar for 3-5 minutes).

Operational Key Points: Thoroughly remove organic matter, blood stains, and cleaning solution residues; sterilize in an exposed state (excluding drying time) and avoid stacking instruments; dry immediately after sterilization and hang vertically to prevent mirror surface scratches.

2.Sterilization of Heat-Sensitive Instruments

(1) Low-Temperature Plasma Sterilization

Applicable Objects: Flexible endoscopes (e.g., gastroscopes, colonoscopes) and optical components.

Sterilization Method: Hydrogen peroxide low-temperature plasma sterilization (sterilization cycle of 45-75 minutes).

Operational Key Points: Ensure instruments are completely dry before sterilization; follow equipment instructions to set parameters and avoid over-sterilization that may cause instrument aging.

(2) Ethylene Oxide Sterilization

Applicable Objects: Rigid endoscopes with complex structures that are heat-sensitive.

Sterilization Method: Ethylene oxide gas sterilization (at a concentration of 600-800 mg/L, temperature of 37-63°C, relative humidity of 40%-80%, for 1-6 hours).

Operational Key Points: Ventilate and aerate for more than 12 hours after sterilization to remove residual gas; regularly inspect equipment for airtightness to prevent gas leakage.

(3) Glutaraldehyde Immersion Sterilization

Applicable Objects: Flexible endoscopes and heat-sensitive accessories.

Sterilization Method: Immersion in a 2% glutaraldehyde solution for 10 hours.

Operational Key Points: Ensure instruments are fully immersed during immersion and all channels are filled with disinfectant; thoroughly rinse with sterile water after sterilization to remove residual disinfectant; regularly test glutaraldehyde concentration and replace it promptly if it falls below the effective concentration.

(4) Low-Temperature Steam Formaldehyde Sterilization

Applicable Objects: Rigid endoscopes with complex structures.

Sterilization Method: Formaldehyde sterilization in a sterilization box (at 54°C ± 2°C, relative humidity of 70%-90%, formaldehyde concentration of 500 mg/L, for more than 3 hours).

Operational Key Points: Evaporate 25% ammonia water after sterilization to remove residual formaldehyde gas; strictly control temperature and humidity to ensure sterilization effectiveness; spread out and leave gaps between sterilized items to avoid sterilization dead zones.

II. Standardized Operational Procedures

Pre-treatment: Immediately rinse the endoscope surface and channels with running water after use to remove blood, mucus, and other contaminants; repeatedly scrub the channels with a dedicated brush to prevent residue from drying and forming a biofilm; limit pre-treatment time to within 10 minutes to avoid microbial growth.

Cleaning: Disassemble instruments and separate all detachable components; soak in warm water containing a multi-enzyme cleaner (water temperature ≤ 40°C), flush the channels internally with a high-pressure water gun, and manually scrub joint areas with a soft-bristled brush; prepare the cleaning solution fresh for each use and do not use it for more than 4 hours; rinse three times with purified water after cleaning to ensure no cleaning solution residue remains.

Drying and Storage: Use filtered dry air and blow air through the channels with an air gun until no water droplets remain; hang flexible endoscopes vertically to avoid damage from bending; maintain storage cabinets at a temperature < 24°C and humidity < 70%, and monitor the storage environment daily.

III. Quality Control and Monitoring

Biological Monitoring: Conduct biological monitoring cultures weekly using Bacillus subtilis var. niger spores as indicator organisms; recall and reprocess all sterilized items from the same batch if biological monitoring fails.

Chemical Monitoring: Affix chemical monitoring cards outside sterilization packs and investigate the cause if color change is uneven.

Physical Parameter Testing: Conduct physical parameter testing of sterilization equipment quarterly, with pressure error within ±0.5 kPa and temperature error within ±1°C; perform a daily no-load B-D test on sterilization equipment and have the manufacturer conduct a comprehensive overhaul annually.

IV. Precautions

Personnel Protection: Cleaning personnel should wear waterproof aprons, goggles, and double gloves, and an eyewash station should be available; the disinfectant preparation area should have an independent ventilation system, and ethylene oxide sterilization areas should be equipped with concentration alarm devices; operators should receive 16 hours of professional training annually, and new staff must pass a practical assessment before being allowed to work.

Instrument Maintenance: Inspect for mirror surface scratches and channel damage after each cleaning, and immediately discontinue use if damage is found; replace sealing rings quarterly and lubricate valves monthly; establish a preventive maintenance plan, with professional calibration of the optical system every six months and replacement of light guide fiber bundles if more than 10% are broken.

Emergency Handling: In case of prion-contaminated instruments, immediately immerse them in 1 mol/L sodium hydroxide for 60 minutes; for mycobacterium contamination, extend sterilization time to 1.5 times the standard cycle; in the event of sudden sterilization equipment failure, activate a backup sterilization plan and prioritize the processing of emergency instruments.