CMDRT - Certified Medical Device Reprocessing Technician Flexible Endoscope Reprocessing Questions and Answers 2 — Questions and Answers

Question 1: What must be performed immediately after a flexible endoscope is used on a patient?

Full immersion in sterilant
Bedside pre-cleaning including wiping the insertion tube and suctioning enzymatic detergent through channels (Correct answer)
Placing it directly into a transport container without any treatment
Running it through an automated endoscope reprocessor

Correct answer: Bedside pre-cleaning including wiping the insertion tube and suctioning enzymatic detergent through channels

Bedside pre-cleaning is critical to prevent organic soil from drying in the endoscope channels. This includes wiping the exterior and suctioning enzymatic solution through the air/water and suction channels while the endoscope is still connected to the light source.

Bedside pre-cleaning is the first and arguably most critical step in flexible endoscope reprocessing. As recommended by CSA Z314.8 and endoscope manufacturer IFU, this step must occur immediately after the procedure while the endoscope is still connected to the light source/processor. The insertion tube is wiped with a lint-free cloth moistened with enzymatic detergent, and enzymatic solution is suctioned through the channels to remove gross soil before it can dry. Air is then suctioned to clear the channels. This step is essential because endoscope channels are narrow (some less than 1mm diameter) and organic matter dries rapidly, forming biofilm that is extremely difficult to remove later. Studies have shown that inadequate bedside pre-cleaning is a leading cause of endoscope reprocessing failures.

Question 2: What is the purpose of leak testing a flexible endoscope before cleaning?

To check if the endoscope needs calibration
To detect damage to the outer sheath that could allow fluid ingress into the internal components (Correct answer)
To verify the light source is working
To measure the diameter of the channels

Correct answer: To detect damage to the outer sheath that could allow fluid ingress into the internal components

Leak testing detects breaches in the endoscope's outer covering that could allow cleaning solutions, disinfectants, or body fluids to penetrate the internal optical and mechanical components, causing costly damage and potential patient safety issues.

Leak testing is a mandatory step in flexible endoscope reprocessing, performed before the scope is immersed in any liquid. The endoscope is pressurized using a leak tester (connected to the venting connector) to a specified pressure, then submerged in water while the technician observes for a stream of bubbles indicating a breach. A damaged outer sheath can allow moisture to infiltrate the internal components — fiber optic bundles, CCD chips, angulation wires, and electrical connections — causing thousands of dollars in repair costs. More importantly, fluids trapped inside the scope cannot be effectively cleaned or disinfected, creating a potential infection transmission risk. If a leak is detected, the scope must not be used and should be sent for repair. Per CSA Z314.8, leak testing must be documented.

Question 3: What is high-level disinfection (HLD) in the context of flexible endoscope reprocessing?

Sterilization using steam under pressure
A process that eliminates all microorganisms except high numbers of bacterial spores (Correct answer)
Simple wiping with alcohol
Low-temperature washing with soap and water

Correct answer: A process that eliminates all microorganisms except high numbers of bacterial spores

High-level disinfection destroys all vegetative bacteria, mycobacteria, fungi, and viruses, and reduces but does not necessarily eliminate bacterial spores. It is the minimum reprocessing standard for semi-critical devices like flexible endoscopes that contact mucous membranes.

High-level disinfection (HLD) is defined as a process that eliminates all vegetative microorganisms, mycobacteria, lipid and non-lipid viruses, fungal spores, and some but not necessarily all bacterial endospores. In Canada, HLD is the minimum acceptable reprocessing level for semi-critical medical devices — those that contact intact mucous membranes or non-intact skin, such as flexible gastrointestinal endoscopes and bronchoscopes. Common HLD agents include glutaraldehyde, ortho-phthalaldehyde (OPA), peracetic acid, and hydrogen peroxide. The choice of agent, concentration, temperature, and contact time must follow both the chemical manufacturer's and the endoscope manufacturer's IFU. CSA Z314.8 specifies the requirements for HLD in Canadian healthcare settings.

Question 4: Why is it essential to flush all channels of a flexible endoscope with alcohol before storage?

To lubricate the channels
To facilitate drying and prevent moisture-related microbial growth during storage (Correct answer)
To sterilize the endoscope
To improve image quality

Correct answer: To facilitate drying and prevent moisture-related microbial growth during storage

Flushing channels with 70% isopropyl alcohol displaces residual water and facilitates drying. Moisture remaining in channels during storage promotes bacterial growth and biofilm formation, which can compromise patient safety.

After high-level disinfection and rinsing, flexible endoscope channels must be flushed with 70% isopropyl alcohol followed by forced-air drying before storage. This step is critical because any residual moisture in the narrow channels creates a favourable environment for microbial growth, particularly waterborne organisms like Pseudomonas aeruginosa, which can proliferate rapidly in moist conditions. The alcohol serves two purposes: it has antimicrobial properties that provide an additional margin of safety, and it displaces water and evaporates rapidly, facilitating complete drying of channels. CSA Z314.8 and Health Canada guidelines emphasize that inadequate drying is a significant risk factor for endoscope-associated infections. Endoscopes must then be stored vertically in well-ventilated cabinets with channel caps removed.

Question 5: What type of brushes should be used to manually clean flexible endoscope channels?

Any brush that fits loosely in the channel
Single-use brushes of the correct diameter specified by the endoscope manufacturer (Correct answer)
Metal wire brushes for thorough scrubbing
Reusable cotton swabs

Correct answer: Single-use brushes of the correct diameter specified by the endoscope manufacturer

Single-use cleaning brushes of the correct size ensure effective soil removal without damaging the delicate channel lining. Reusable brushes can harbour microorganisms and contribute to cross-contamination.

Channel brushes for flexible endoscope cleaning must be single-use (disposable) and sized according to the endoscope manufacturer's specifications for each specific channel. Using a brush that is too small will not adequately contact the channel walls, leaving soil behind. A brush that is too large can damage the channel lining, creating surface irregularities where biofilm can develop. CSA Z314.8 recommends single-use brushes because reusable brushes, even when cleaned and disinfected, can harbour microorganisms in their bristles and wire cores. The technician must brush each channel until the brush comes out visually clean, typically requiring multiple passes. Brushes must be inspected before use for missing bristles that could detach and remain in the channel.

Question 6: How should a reprocessed flexible endoscope be stored to minimize recontamination?

Coiled in its carrying case
Hanging vertically in a clean, well-ventilated drying cabinet with caps and valves removed (Correct answer)
Laying flat on a countertop
Immersed in disinfectant solution

Correct answer: Hanging vertically in a clean, well-ventilated drying cabinet with caps and valves removed

Vertical hanging in a ventilated cabinet allows residual moisture to drain by gravity and air to circulate through channels. Removing caps and valves facilitates drying and prevents moisture trapping that promotes microbial growth.

Proper storage of reprocessed flexible endoscopes is essential to maintain their microbiological safety until next use. CSA Z314.8 specifies that endoscopes should be stored vertically (hanging from their connector end) in a dedicated, clean, well-ventilated drying cabinet. The cabinet should have HEPA-filtered air circulation. All caps, valves, and buttons should be removed to allow air circulation through internal channels. The endoscope should not contact other scopes or cabinet walls. Coiling scopes in cases traps moisture and prevents airflow, promoting microbial growth. Storage in disinfectant solution is no longer recommended as it can damage the scope and the solution may become contaminated over time. Many Canadian facilities now use automated endoscope storage and drying cabinets with controlled airflow.

CMDRT - Certified Medical Device Reprocessing Technician Flexible Endoscope Reprocessing Questions and Answers 2

What must be performed immediately after a flexible endoscope is used on a patient?