The flexible endoscope is a sophisticated medical instrument, essentially a long, narrow tube equipped with a camera, light, and working channels, used to visualize and operate within internal body cavities during procedures like colonoscopy and gastroscopy. Because these devices enter normally sterile or semi-sterile areas of the body, they carry a significant risk of transmitting infection if not properly cleaned between patients. Reprocessing an endoscope is a multi-step, highly rigorous protocol governed by regulatory bodies to ensure patient safety and prevent healthcare-associated infections. This comprehensive process must systematically remove all organic material and destroy microorganisms, which is challenging given the instrument’s narrow channels and complex design.
Immediate Care and Pre-Cleaning at the Bedside
The reprocessing protocol begins immediately after the endoscope is removed from the patient, a phase known as pre-cleaning or point-of-use treatment. Immediate action is required to prevent biological material, such as blood, mucus, and tissue debris, from drying onto the scope’s exterior and within its narrow channels. Allowing organic soil to dry and harden forms a biofilm, which makes subsequent cleaning and disinfection steps ineffective.
The first step involves wiping the entire exterior of the insertion tube with a soft cloth or sponge soaked in a freshly prepared detergent solution. Next, the technician flushes a large volume of the detergent solution through the working channels, such as the biopsy and suction channels, until the fluid exiting the scope appears completely clear of debris. This flushing step is important for removing the bulk of contaminants from the internal pathways.
Finally, the endoscope is disconnected from the light source and suction apparatus, and all detachable valves and accessories are removed. The scope is then placed in a covered, sealed container for safe transport to the dedicated reprocessing room. Manual cleaning must begin quickly, often within 60 minutes of the procedure’s end, and the container keeps the scope moist until that time.
Manual Cleaning and Preparation for Disinfection
Upon arrival at the reprocessing area, the endoscope undergoes meticulous manual cleaning, which is the foundation of the entire process. Residual organic matter shields microorganisms from chemical disinfectants used later. The first action taken is a leak test, which involves pressurizing the endoscope with air while it is submerged in water to check for tears or breaches in the outer sheath.
If a leak is detected during the test, the endoscope must be immediately pulled from service for repair, as fluid infiltration during later reprocessing steps could severely damage the instrument’s sensitive internal electronics and fiber optics. The leak test ensures both the functionality of the device and the safety of the reprocessing environment. If the leak test passes, the scope is kept fully immersed in a fresh, approved detergent solution, typically a neutral pH, low-foaming detergent, throughout the entire manual scrubbing process.
The technician systematically brushes all accessible channels, including the biopsy, suction, and air/water channels, using specialized, length-appropriate brushes. The brush must be run through each channel multiple times, and the tip must be inspected after each passage to confirm that all visible debris has been removed. Brushing continues until the brush tip exits the channel completely clean. Once brushing is complete, the channels are flushed again with the detergent solution to ensure all loosened debris is washed away.
High-Level Disinfection and Automated Reprocessing
Following thorough manual cleaning and rinsing to remove all traces of detergent, the endoscope is ready for High-Level Disinfection (HLD). HLD is a validated process that destroys all microorganisms on the endoscope, with the exception of a high number of bacterial spores. Since the endoscope is classified as a semi-critical device, HLD is the standard of care for rendering it safe for reuse.
Most modern facilities utilize an Automated Endoscope Reprocessor (AER) to perform this step, as it standardizes the process and minimizes human error. The AER automates the circulation of the liquid chemical germicide, such as ortho-phthalaldehyde (OPA) or glutaraldehyde, through all internal and external surfaces of the endoscope.
The AER ensures the precise contact time and temperature required for the disinfectant to be effective against a broad spectrum of pathogens. It also automatically monitors the disinfectant’s concentration. The effectiveness of the HLD process is entirely dependent on the disinfectant physically contacting all surfaces for the specified time, which is only possible if the manual cleaning step has successfully removed all organic matter beforehand. Once the disinfection cycle is complete, the AER moves to the rinsing phase, which is a crucial step before the scope is handled again.
Final Rinsing, Drying, and Safe Storage
The disinfection phase is immediately followed by a meticulous rinsing process to remove all residual traces of the toxic high-level disinfectant chemical. This rinsing is performed with sterile or filtered water to prevent the reintroduction of waterborne microorganisms. Failure to thoroughly rinse the scope can result in the chemical being transferred to the next patient, causing irritation or chemical burns.
Following rinsing, the endoscope must be aggressively dried, a step that prevents bacterial regrowth. Residual moisture is the primary cause of microbial proliferation and biofilm formation within the endoscope’s channels during storage. The drying process involves flushing all internal channels with medical-grade alcohol (70% to 90% isopropyl alcohol), which is then immediately followed by a purge of filtered, forced air.
This combination of alcohol and forced air physically removes moisture and facilitates rapid evaporation, ensuring that the internal lumens are completely dry. The endoscope is then transported to a dedicated storage area and hung vertically in a specialized cabinet that circulates HEPA-filtered air. Vertical storage facilitates drainage and continued drying, and all detachable components must be removed and stored separately to maintain the scope’s state of high-level disinfection until its next use.