Practical Gastrointestinal Endoscopy

18
CHAPTER 2
• Clean all instrument accessories equally scrupulously, including
the air/water and suction valves, water bottles and the cleaning
brushes.
Disinfection
After thorough cleaning:
• attach the manufacturer’s cleaning adapter to the suction,
biopsy and air/water channels;
• flush each channel with detergent fluid ensuring that it emerges
from the distal end of each channel;
• confirm that all air is expelled from the channels. Soak the
instrument in the chosen disinfectant for the recommended
contact time.
Disinfectants
Glutaraldehyde is the most popular agent. It can destroy viruses
and bacteria within 4·min, is non-corrosive (for the endoscopes),
and has a low surface tension, which aids penetration. Most advisory
authorities recommend a 20-minute soak time in glutaraldehyde
for standard situations, assuming adequate precleaning.
More prolonged soaking may be required in cases of known or
suspected mycobacterial disease. The instrument accessories
(valves, water bottles, etc.) are also soaked.
Glutaraldehyde does carry the risk of sensitization, and can
cause severe dermatitis, sinusitis or asthma among exposed
staff. The risk increases with increasing levels and duration of
exposure. Heavy domestic-grade rubber gloves should be worn
when using glutaraldehyde since normal thin medical glove
material is permeable to it, and goggles and/or a face mask can
protect against splashes. Closed system reprocessors and fume
hoods/extraction fans are important. Reprocessors should be
self-disinfecting. The concentration of disinfectant should be
monitored.
Alcohol, peracetic acid, chlorine dioxide, Sterox and other agents
have also been used for endoscope disinfection.
A sterile water supply (special filters may be needed) helps to
reduce the risk of nosocomial infections, such as Pseudomonas.
Rinsing, drying and storing
Following disinfection, reprocessors rinse the instruments internally
and externally to remove all traces of disinfectant, using
the all-channel irrigator. The air, water and suction channels are
perfused with 70% alcohol and dried with forced air before storage.
This must be done manually if reprocessors are not used.
Bacteria multiply in a moist environment, and the importance
of drying instruments after disinfection cannot be overempha-