CER Scope Inspection and Testing Questions and Answers 2 — Questions and Answers
Question 1: What is the correct procedure for performing a leak test on a flexible endoscope?
- Immerse the endoscope in water, then attach the leak tester and pressurize
- Attach the leak testing device and pressurize the scope before immersion, then submerge and look for air bubbles (Correct answer)
- Attach the leak tester after HLD to check for leaks at the end of reprocessing
- Squeeze the insertion tube and check for resistance
Correct answer: Attach the leak testing device and pressurize the scope before immersion, then submerge and look for air bubbles
The scope must be pressurized before immersion; air bubbles visible after immersion indicate a leak in the outer sheath.
The correct leak test sequence: (1) attach the leak testing device to the venting connector, (2) pressurize the scope to the manufacturer-specified pressure, (3) confirm pressure holds while the scope is on the bench (initial check), (4) submerge the fully angulated scope in water and observe all surfaces for continuous streams of bubbles indicating a breach. Moving all angulation controls and examining the bending section, insertion tube, and distal tip is required. Pressurizing before immersion ensures any leak is revealed rather than allowing fluid ingress.
Question 2: What does a positive leak test result look like when the endoscope is submerged?
- Water turning a different color
- Continuous stream of air bubbles emerging from the same location on the endoscope (Correct answer)
- The endoscope sinking to the bottom
- Pressure gauge reading increasing
Correct answer: Continuous stream of air bubbles emerging from the same location on the endoscope
A leak is indicated by a continuous stream of bubbles at a fixed location, showing air escaping through a breach in the endoscope's outer sheath.
During a leak test, a few bubbles may appear immediately upon submersion from air displaced by the water — these are normal. A leak is identified by a continuous stream of bubbles emerging from a consistent location on the scope. Common leak locations include the bending section (most frequently damaged by bites or wear), around channel ports, through the distal tip, or along the insertion tube. The location of bubbles guides repair diagnosis. Single or intermittent bubbles may indicate small leaks and should also be investigated.
Question 3: During visual inspection of a cleaned endoscope, which finding requires immediate removal from service?
- Slight surface dullness of the insertion tube
- Visible crack in the bending rubber or detachment of the distal tip cap (Correct answer)
- Minor scratching on the control body
- Stiff angulation lock knob
Correct answer: Visible crack in the bending rubber or detachment of the distal tip cap
Visible cracks in the bending rubber or detachment of the distal tip cap represent structural failures that compromise both scope integrity and reprocessing effectiveness.
Cracks in the bending rubber section allow fluid ingress into the complex mechanical structures of the bending section, which are essentially impossible to clean and disinfect. Detachment of the distal tip cap exposes optical and mechanical components to patient contact and contaminants. Both are patient safety hazards and typically cause leak test failure. Surface dullness, minor scratches on handle housing, and stiff (but functional) knobs may be documented and monitored without immediate removal unless they progress.
Question 4: What is the purpose of angulating the endoscope in all four directions during the leak test?
- To test the flexibility of the angulation wires
- To expose the bending section in different positions, revealing leaks that may only manifest under stress (Correct answer)
- To lubricate the angulation mechanism
- To verify the scope is not kinked
Correct answer: To expose the bending section in different positions, revealing leaks that may only manifest under stress
Different angulation positions stretch different parts of the bending section, revealing small leaks that may not be visible with the scope in the neutral position.
The bending section consists of flexible rubber that is stressed during use when the tip is deflected. Small breaches in the rubber may not be apparent when the scope is straight because the rubber compresses over the defect. Fully angulating the scope in all four directions (up, down, left, right) stretches the bending rubber to its maximum in each direction, opening any small cracks and revealing them with bubbles during the leak test. Failing to angulate during the leak test misses the most common location of leaks.
Question 5: What is an endoscope's 'channel patency test' and why is it performed?
- Testing that channels can withstand high-pressure flushing
- A test confirming that channels are open and not blocked, typically by passing air through each channel and confirming flow (Correct answer)
- Measuring the diameter of the biopsy channel
- Checking that channel caps are securely attached
Correct answer: A test confirming that channels are open and not blocked, typically by passing air through each channel and confirming flow
The channel patency test confirms that all channels remain open and unobstructed, ensuring that fluids and cleaning tools can pass through during reprocessing.
A channel patency test involves connecting a syringe or air/water supply to each channel port and confirming unobstructed air or water flow through to the distal tip or exit port. Blockages can result from aspirated foreign material (food, tissue), broken cleaning brush bristles lodged in a channel, or precipitation of cleaning chemicals. A blocked channel cannot be adequately brushed or flushed, making it impossible to clean or disinfect. A scope with a blocked channel must be removed from service for repair.
Question 6: How should the insertion tube be inspected after cleaning?
- Visual inspection only from 1 meter distance
- Wipe the insertion tube from distal to proximal with a damp cloth and visually inspect the full length for bends, kinks, cracks, or discoloration under good lighting (Correct answer)
- Only the distal 20 cm requires inspection
- Inspection is not required between procedures for the same patient
Correct answer: Wipe the insertion tube from distal to proximal with a damp cloth and visually inspect the full length for bends, kinks, cracks, or discoloration under good lighting
The full length of the insertion tube must be inspected under good lighting for any structural defects that compromise safety or reprocessing effectiveness.
A complete insertion tube inspection involves running a lint-free cloth along the full length while visually inspecting for: surface breaks or cracks, kinks or bends that may indicate internal damage, unusual discoloration (may indicate chemical damage or manufacturing defects), areas of increased flexibility (possible internal wire damage), and damage to any external markings. This inspection should occur during manual cleaning and again during the pre-HLD check. Any abnormality should be documented and evaluated for removal from service.
CER Scope Inspection and Testing Questions and Answers 2
What is the correct procedure for performing a leak test on a flexible endoscope?